I have a bike, but I love my Bixi membership. It's about 100$/year and you can take trips of 30-45 minutes (45 if you extend) almost anywhere downtown. Sometimes I bixi home from friends' houses late at night and save the 3$ the TTC would have cost me. There's also a free iphone app (spotcycle) that makes it easy to check if there are bikes and docks available where I need them to be.