There's a LARGE number of solutions, but they don't all need to take the oil out of your life...
(1) Take a bicycle, tricyle, folder, recumbent, you name it.... and strap a motor on it.
This is a guide I wrote years back when I was learning how to do it myself. I've got a 4-stroke 33cc Robin Subaru motor on a folder now that gets close to 200mpg. Read my lips. 200. Miles. Per. Gallon. For the extra slow, that means with a ONE Gallon can, I am able to ride for 200 miles... and since it's a 4-stroke, I can just fill'er up at any ol' gas station. Unfortunately, this 20" folder has a poor frame choice, and there's one thin aluminum tube that cracked away from the crank bracket. I'll be welding it sooner or later, but the thing has a dual-freewheel setup... and just one gear. So I just go. Tops out at 25 mph, but the 2-stroke could get up to 30 mph... just had to mix oil, which isn't bad at all. I've got a Mitsubishi 33cc motor that I'm going to be putting on a better frame when I get a chance. You can use an electric motor setup if you prefer, but I'm not ready for expensive batteries with limited range & life cycles. Those things are still cheap and impractical, IMHO.
(2) Put a motor on a Swifty One scooter...
http://www.swiftyscooters.com/index.php/swifty-one
(3) Put a motor on a pedal plane and take to the skies...
http://www.youtube.com/watch?v=3XqNwrVfSx4
(4) Put a motor on a hydrofoil and take it down [and even back UP] the rivers...
http://www.youtube.com/watch?v=RaYhyeGxYoA
- OR, if you want to buy the thing already built, and you're stuck on electric. How about...
(5) Ryno's electric-powered one-wheeler...
http://www.youtube.com/watch?v=Z1YoCfm7nxU
(6) Electric, Self-balancing, HANDS-FREE Unicycle (with seat) - SBU v3...
http://focusdesigns.com/media/#videos
(7) Electric, Self-balancing, HANDS-FREE "Wheel" (no seat) for $1800 - SoloWheel...
http://www.youtube.com/watch?v=JkCr1KmEXos &&
http://www.youtube.com/watch?v=8soCqO5ok6U
(8) Tilting, 3-wheel electric scooter - Sway Motorsports...
http://www.gizmag.com/sway-motorsports-scooter/22117/
(9) The lightest electric vehicle - Boosted Boards...
http://www.gizmag.com/boosted-boards-skateboard/24111/
- OR, perhaps you're a purist, like those who post pictures of road bikes. You want to do nothing but eat gas and burn fat?? Here ya go...
(10) Put your ride in the trunk, or ten of them, even. Take one on the plane...
http://www.motoredbikes.com/showthread.p...ding-Bikes-quot
(11) Put your ride in your pocket(s).
Freeline Skates or
HypnoSkates