Usually, I like to keep my hands on the grips and my eyes on the road. I occasionally wave to anybody that seems like they know what they are doing. Mostly I just give a nod but if something catches my eye I'll make an effort to wave.
I personally do not like scooters for many reasons- Anybody can get one with little to no training, no license, no registration, no helmet, no regard for their safety or anybody else's.
In an urban setting as well as a college town like Boston, it is all too common to see stupidity brought to an art form. College kids riding around in heavy traffic, with flip flops on their feet. Weaving in and out of lanes. I can't tell you how many times I've seen people talking on cellphones while riding with one hand, or worse, holding the phone to their ear with their shoulder while riding. I once saw a young girl texting while she rode her scooter. I wanted to stop and scold her, as well as find out how the hell she was doing it. Then there's my biggest pet peeve that I see all the time... idiots that wear a full face helmet propped up on their forehead. If there's an easier way to snap your neck, please let me know.
I also know quite a few people that lost their licenses due to DWI, stupidity, etc., who solve the problem by getting a scooter. Every single one of them has crashed at least once. One died on impact.
Another reason I do not like scooters is that they can go anywhere a car or motorcycle can go and often ignore basic driving rules but don't require you to register them or insure them. Also, they can park anywhere, even the sidewalk (I know a little girl that was burned when she touched the muffler of a scooter parked on the sidewalk). This rubs me the wrong way because I have to pay insurance, excise tax, title fee, and registration but am limited to parking only in designated parking spots. Parking is a particular issue in Boston. It wouldn't surprise me to park my bike at a meter, between two cars, and come out later to find a ticket on my bike. Once I had parked my bike at a meter, fed the quarters in, only to find later that a metermaid ticketed my bike but not the car that parked there after I did.
Many scooter riders are responsible folks just looking for a cheap simple form of transportation but a lot of them are reckless, poorly trained, oblivious to the dangers for them and others, and think it's just a chair with wheels. I equate the scooter and motorcycle to a 12 gauge shotgun and a 22 caliber handgun. Sure, the shotgun will blow your head clean off but the saturday night special will still kill you just as dead.