1. A sturdy piece of wood about 3/4 inch thick, about 34-36 inches long by 14 inches wide
   Plywood is cheap and works well, but pretty much any scrap wood will do, but avoid pine since it bends over time.
   
2. Three Wood strips about 3/4 to 1 inch by x 1 inch in the following approximate lengths: 30 inches and two 14 inch strips
   I used some scrap oak strips from some shelving; you can use any kind of wood trim, but I'd stick with the harder woods -- oak, maple, mahogany, etc and avoid soft woods like pine)
   
3. PVC pipe: Two 4x2 inch bushings and a short length (3 inches) of 2-inch diameter PVC
   Available from any hardware, home supply store. Should cost about $8-10 total
   
4. PVC primer and glue
   Available from any hardware, home supply store. Should cost about $1.50 each
   
5. Twelve (or so) Flat Head Wood screws between 3/4 inch and 1 1/4 inch long
   Don't use drywall screws (they're too weak). I used 1 inch brass screws I found lying around.
   
6. Wide (4" or more) adhesive backed grip tape
   For both the top of the board (for non-slip purposes) and for covering the roller (PVC doesn't grip too well on its own. Also, with the grip tape on the roller, it'll scratch the hell out of your soon-to-be-Ex-girlfriend's nice hardwood floors!!)

Optional:

1. Strong Wood glue
   Liquid Nails works best; for added strength in keeping the pieces together
   
2. Strap material about 36 inches long
   Flat nylon works well -- I used an old camera strap. This serves two main purposes: 1) it keeps the roller from flying past the stop (so you avoid a face-plant) and 2) it keeps the roller attached to the board so you won't lose one part without losing the other.

Tools Required:

• A saw (preferably a table saw or jigsaw, if you can cut straight)
• A jigsaw (for notching the stopper pieces; helpful, but not required)
• A drill (for drilling pilot holes)
• Sandpaper (if you're painting your board and/or applying grip tape)
• A screwdriver
• A file
• Paint, Paintbrush, etc... (if you're painting your board)

My Board's Dimensions (for reference; you can alter any of these to suit your taste)

• Board: 36 inches long by 12 inches wide by 3/4 inch thick
• Track: 3/4 inch wide by 1 inch tall by 25 1/2 inches long
• Stoppers: 3/4 inch wide by 1 inch tall by 8 1/2 inches long
• Strap: Flat 3/4 wide nylon about 28 inches long

Things to Consider:

• Don't make the stopper too wide for the board
• If you use grip tape on the roller, it WILL scratch wood floors. Either use it on a piece of scrap carpet, or cover the roller with non-marking rubber instead.
• The bigger the roller, the harder to balance (and the easier to get hurt)
  

I've tried to outline the major steps in piecing together your board below. I'd appreciate any help in revising these instructions at bongoboy@belikemichael.com.

1. CUT BOARD: Cut a sturdy piece of wood or plastic (3/4" or thicker) 34-36 inches long and 12-14 inches wide. If the board is for adult use, go with the bigger dimensions (36" x 14"), but for kids, you can make it smaller.
    
2. PAINT BOARD (Optional): If you are going to paint your board, do so before moving on to the next step.
    
3. CUT "H" PIECES: Cut the three strips of wood strips that will be used for the "H" on the underside of the board. The "H" is actually more of an "|----------|" shape, but it's easier to call it an "H". The "H" serves as the track or guide (the long part) and the stopper (the short ends) for the roller.
   
   I used some 1 inch oak strips from a shelf I wasn't using. The pieces are 1 inch thick by about 1 1/2 inches wide. For the length: two of the pieces will be about 2 inches less than the board's width (about 12 inches) and the third piece will be about 26 inches long. Cut them a little longer initially as you can always shorten them later. Put these three strips aside for now -- do not attach the pieces to the board just yet.
    
4. ROLLER ASSEMBLY: The roller will be made from the two PVC 4x2 inch bushings and the short (3 inch) piece of 2 inch diameter PVC. Each bushing acts as a "wheel" connected witht the 2 inch piece serving the role of an axle between the two bushings. When working with PVC, I advise one thing: DRY FIT EVERYTHING BEFORE GLUING!!!
   
   After dry fitting everything, glue the short 2 inch diameter piece into one of the bushings, on the 2-inch opening side of the bushing. Then, before gluing the second bushing onto the 2 inch piece, take the long "H" strip of wood (the "track") and a thin piece of cardboard (or just eyeball it) to gauge the size of the gap between the two bushings. The idea here is to assemble the roller so that the roller can freely glide along the track without pinching the track AND not be too big as to slide off the track AND accommodate the height of the track without hitting the roller's axle. I used a gap of about 1/16 inch to give the roller very limited movement. Mark and cut the 2 inch PVC to the right length for the track and glue the remaining bushing onto it.
   
   Finally, apply adhesive grip tape to the outside of the two bushings, cutting away any slack from the edges.
    
5. ATTACH THE "H" TO THE BOARD: Now that the roller is complete, you need to place the "H" pieces on the board itself. Place the "stopper" pieces first.
   
   The easiest way to gauge where to place the stoppers to place the board on top of the loose roller and, while keeping one end of the board on the ground, slide the roller toward that end, without raising that end off the ground. The other end of the board will rise as you move the roller. Stop moving the roller when the high end of the board is at about a 30 degree angle (you can go more or less here) and mark the roller's position and mark the relative position of the stopper (that is, where the stopper would have to be to stop the roller at that point.)
   
   Cut the stopper pieces to the right length (in about 1-2 inches from each edge) and notch them (I used a jigsaw) so they fit nicely together with the track piece.
   
   Once positioned on the board's underside, cut the track piece to the correct length. Glue and screw all three pieces to the board (use short screws that don't stick through the board.) The main idea here is to disallow any extreme angle the board may reach. Since you'll be standing on it, you want only comfortable, safe angles of motion, otherwise you may get thrown off it long before the roller hits the stopper.)
    
6. ATTACH THE STRAP: Cut a thin, but strong piece of nylon (or similar material) to hold the roller in place. The easiest way to measure for length of the strap is to first screw one end of the strap to one of the stoppers (opposite where the track is notched into it). Then move the roller all the way toward that stopper and hold the loose end of the nylon to the same spot on the opposite stopper. Add a little extra (about 2 inches) before you cut it.
   
   You want the strap tight enough to hold the roller, but not so tight as to restrict the roller's free motion (it MUST move freely from stopper to stopper.) Attach the loose end to the opposite stopper using a screw.
    
7. GRIP TAPE: Apply grip tape to the top side of the board wherever feet are likely to be (at the ends).
    
8. To use your Bongo Board, you simply stand on it (one leg at a time helps) and try to balance it on the roller without letting either end of the board hit the ground. You can try for full swing motion or simply try to keep the board still and horizontal. You can also try for a specified length of time or whatever you can dream up! Let a kid try it -- they're likely to come up with the best ideas for contests and games!
    
   Put on a helmet and enjoy your new Bongo Board, courtesy Belikemichael.com!!
    
9. Take pictures of your new creation and send them to bongoboy@belikemichael.com!

My board took me about 2 hours total work (including the quick 'n dirty 3 coat paint job), spanning an evening. If you're not painting it, yours will go much quicker (about an hour or so).
 
If you need any help along the way, let me know.