Wii is bumped down the priority list, Bike moves up.

With the trip to Florida coming up fast, and the summer weather already arrived.  I’ve had to reduce the importance of getting a Wii,  maybe I’ll get one for the fall.  By then I shouldn’t have to wait in lineups at 4am. 
Bumping the Wii down the list moves my next priority up the list.  I’d like to have a peddle bike for the summer.  Two reasons, 1. it’s much easier to get around on a bike, and faster than the bus for anything downtown, and 2. it’ll be nice to get outside for the exercise.
I don’t want to spend too much on a new bike so I’m trying to track down a used one.  hopefully I can keep the purchase under $200.  I’m on the fence deciding what kind of bike to get.  Part of me wants to get a road bike, or one like the couriers use to get around town,  the other part sees the practicality of a mountain bike.
Some research tells me that the courrier bikes are usually built from parts, as the guys riding them don’t usually make enough to buy expensive bikes.  I’m kind of intrigued about the idea of building my own bike but I’m not too sure where to get used bikes/parts though.
Either way.  I’ll have to wait to get a bike until at least late May after we get back from Florida.