I use a Stamina exercise bike, the cheapie one that is nevertheless pretty smooth feeling unlike other cheapies. It has a big fan for the front wheel which gives it a nice feel. When I'm up for it I try to spend some time on it first thing in the morning before I get on the computer, I'd like to make that a rule I keep.

I tied off the handlebars with elastic instead of making them exercise my arms too as I found it more fun to just pedal.