The original project for this was called the Human Hockey Puck it
was out of U of V (from what I have found). It has been done many
times but I think I have some improvements that can help you build
one in about an hour.

Drawing are not to scale, for illustration only.

Step 1: Materials

4ft x 4ft Sheet of ½ inch plywood
5ft x 5ft Piece of 6 mil poly
4 ½ inch pan head screws
20 or so 1 inch pan head screws
Duct tape (about 60 yds)
1/4 inch staples, construction type
Plastic Coffee can lid (or Cool Whip)
4 Felt floor saver pads
Leaf blower (electric)

Step 2: Cutting the Plywood.

Plywood ½ inch, 4ft x 4ft ( drill small pilot hole center)
Cut circle with 2ft 2in radius (Orange)
Cut circle with 2 ft radius (Blue)
Cut shape of leaf blower head ½ way between the center and the
edge (Green) SAND ALL EDGES

Step 3: Center Plastic Cover and Lid.

Screw a 1 inch screw through the center of the disk (just
protruding from the other side). Completely cover the disk with 6
mil poly (leave 4 inches extra all around), use a screw through
the center of the disk (point to plastic). Place the coffee can lid in
the center of the disk use the screw again to make it easy (a small
hole in the center of the lid will help). Secure the lid with 4 screws.
Remove the center screw you used to center the disk.

Step 4: Secure the Cover.

Wrap the plastic over the edge do not tighten it, staple it
about every 4-6 inches, 2-3 inches from the edge. Cut the
excess plastic but leave at least an inch beyond the
staples. Duct tape over the staples and and at least 3
inches onto the disk to about 1 inch from the edge. More is

Step 5: Clamp the Poly Down.

With the circular 2 inch strips cut in step one(Orange) use a
saw to cut off the sharp points . Pre-drill the strips about every 4-6 
inches for the body of the screw. Form a perimeter
covering plastic / duct tape seam, about 1 inch in from edge
install the 1 inch screws in the pre-drilled
holes. There will be gaps space them if you can.

Step 6: Cut the Air Holes.

Flip the disk over. You are going to make 8 holes (Purple) in the
plastic. Each hole is centered 5 inches away from the edge of the
coffee can lid 1.75 inches in diameter. Make the holes using an Xacto
knife. I used a hole saw bit as a guide. Neatness counts tears in the
plastic will make it rip later. Also try to be uniform about the disk, as it
will help support the disk evenly. While you are at it, place duct tape
over the screw heads and place 1 floor saver disk (felt stick on disks)
near each screw one in the center for good luck. This may save your
floors (mine did not scrape but better safe than sorry).

Step 7: Let It Fly (or Hover in This Case)!

Home stretch,  place the leaf blower into the
custom hole in the top and duct tape the heck out of it. Place the
finished unit on a flat clean floor. Plug it in and turn it on to test for
leakage, it should inflate. Shut it off, duct tape the leaks, place the
first rider in the center and turn it on. It will inflate and he will start to
hover, give a slight push and the disk should move easily. Have an
adult ready to pull the plug if there is any problem. Friction is now a
thing of the past, use a second blower to try out propulsion. Wear

The one pictured here does not have the strips, my new design does. 
With my leaf blower, on low you could lift a 160lb person. If it were on high you
get an oscillation above that weight high was fine, your results may vary.