I *love* my bike in BA. It's my primary mode of transport and I wouldn't have it any other way. Do some searches for threads that talk about it (I'm a big advocate) but I can clearly divide my life here into two chapters: before/after bike. Don't worry about the naysayers, in general biking here is generally safe (as long as you stay aware and keep your eyes open--just like any big city) and it's faster, more enjoyable, and the cheapest mode of transport around. The streets are relatively flat so you don't have to worry too much about any hills, and as long as you have a good lock (don't leave your bike out too long anywhere, esp. after dark) you'll likely hold on to your bike to ride another day. You can explore a lot more easily with a bike here, too, as it earns you a certain degree of invisibility that you don't get on foot/taxi/bus. Honestly I find cars are generally more respectful of bicyclists than pedestrians, but watch out especially for taxis and busses.