I actually bought a scooter for that reason myself. Much better than a motorcycle, but also takes a good amount of time out of my day.
I bought a Honda Ruckus for $1200. It gets just shy of 100MPG. If it weren't 49cc and so slow, I'd love to see what MPG I could get out of it hypermiling. But alas, I have to stay on it full throttle 90% of the time just to keep up with traffic. Anything over 40MPH is good, with 45 if I'm lucky downhill.
I drive it daily to work which is 26 miles each way - no joke!
I ride it every day, rain or shine. I haven't driven a car at all since the big tropical storm that flooded my area (well one trip, but that was to SELL the car).
I found a route which is pretty scooter friendly and isn't any longer than taking the highway. Between the gas and insurance savings, I'm saving at least $160 per month. It will pay for itself with those savings by March (assuming I can bear the cold, but I'm in FL, so it shouldn't be a problem).
With a motorcycle (even a Ninja 250 which I'll probably get after this pays itself off), I'd be getting less MPG and have to pay insurance, plus the initial higher cost. Tires for the Ruckus are cheap too. I got Pirellis for $55 with a coupon from CycleGear. That was for the pair, and I mounted them myself.