Vagabond, Pilotpip offers perfectly good advice on this. Manufacturing plants like to keep trikes on the floor because they are so durable and they do not require much maintenance. But they are heavy and not at all suited to extended riding on non-level surfaces; the plant environment is flat and small by comparison. Trikes are like dumptrucks and are not that much fun to ride so I am sure the novelty of it will wear off when you realize you have gone 2 miles and you are already tired. Weight is the arch enemy of the bicycle no matter what the design, and for this reason you are best trying to learn to ride a two wheeler. You will have more options in terms of styles as well as places to go on them. If you really insist on a trike, then I recommend doing your shopping homework carefully with an aim to finding the lightest one you can. Be prepared to spend a lot of money, two to five grand, because the lightest materials are titanium and carbon fiber or a combination of carbon fiber and aluminum parts and these materials are far more expensive.

In the meantime you could buy a quality aluminum or molybdenum steel two wheeler for less than two grand. Balancing on a bike is not that hard as long as you maintain forward motion of a few mph. There are simple 3 speed bikes on the market with frame cutouts for your legs to drop through as soon as you feel your balance is giving out. There is also at least one brand of bike without any gears at all. It has a variable gear ratio that changes as you speed up using flyweights for shifting. If you want a good two wheeler look at Trek, Cannondale, Bianchi, Lemond to name a few.

As for helmets they are an absolute necessity for a novice rider. They are also recommend for advanced riders too, but there are times when it is arguably not required but you definitely will need one. Try a bunch of them on in the store and see which one gives good enough comfort while allowing you to turn your head. Rear visibility is a problem with helmets but mirrors on the helmet can help. I recommend staying off the streets until you are proficient in stopping, starting, one hand riding using the other for hand signals, and you know how the bike reacts to a variety of surfaces types like pea gravel and grease spots. Carry some water and have a flashing LED light on the back of the seat.

There was an argument on talk radio yesterday about bicycle behavior and car- bicycle conflicts in traffic. The car people were saying the commuter bicyclists are generally lawless and unpredictable. They said it bothers them when that bikes do not realibly follow the same traffic rules and are not even held responsible for their behavior. The commuter bicyclists were saying that in this country there are not enough infrastructural accomodations for bicycles, bikes are simply not cars and they do not have the same need for traffic control devices that cars require, and that rather than being a nuisance to motorized traffic they are actually a way to reduce congestion on roads. This in turn saves on road maintenance and reduces the demand for gasoline. I thought it was an interesting discussion.