Building a Mutt (http://www.instructables.com/id/Motorized-Uniwheel-Toy-Thing-Mutt/) is great fun, doesn't take but a few dollars in parts, doesn't require any special tools. The following steps show how to build one. If you don't have exactly the same components, then improvise, thats what I did.
Needle nose pliers, screw driver, drill.
jump rope (the one that has metal bearings)
an old dvd/cd player (computer or otherwise) from which you will scavage:
- motor, motor pulley, motor drive belt, rubber grommets
Erector set type metal strips
plastic coated hanger
two small wheels, beads, metal washers
9 volt battery and battery connector
one electric slide switch
Construction time: about 3 to 4 hours
Step 1: Jump Rope Wheel Bearing
Remove the end caps, push the rope out the open ends and cut them off.
You will be using both end caps and one of the handle tubes to make the wheel bearing.
Step 2: Cut the Bearing Parts
Do the same with the second end cap.
Cut about 1/2 inch from one of the remaining handles to use as the bearing center section.