I've just registered in the poll and it seems I'm the only one who hit 'motorcycle'. Which I thought was odd!
So I thought I'd better put a word in for the humble moped that probably carries thousands of DMs and Instructors to work everyday all over Thailand, Indo and the Carribean.
I've had several 'island 'peds' and they are always wrecks -the better ones are usually hired out at great expense to tourists or rich instructors.
My last moped on Koh Tao had bald tyres, no back brake, a slipping clutch, a slow puncture on the front and an air filter that appeared to have been fashioned from a pair of ladies tights. It had somehow done over 50,000 miles -not bad on an island five miles by two! I only crashed it twice, once into a rock that 'appeared' in the middle of the track and once into a taxi drivers door. Luckily both times I just dusted off and was on my way. Amazing since I was just wearing shorts at the time.
The flip side however, (I'd better balance this post) is the number of people who don't walk away from stacking these things -there was apparently 82 deaths on Koh Samui in 1999. Generally speaking I'd advise any travelling divers to stay away from hiring bikes in Asia unless they have massive riding experience. I'm a qualified motorcycle instructor and even though I coached a few novices on the island I always said that I'd rather they didn't ride at all. Even if a bike is 'twist and go' it doesn't make it 'easy' for a novice to ride. Learn to ride in your home country first, is my advice
If you do ride already however, motorbikes are fun and convenient and their use does fend off (for a while) the inevitability of small tropical islands becoming choked with Suzuki Jeeps.
Phil TK