In reply to frankbabs:
I do a fair bit of cycling and go to a spinning class, but thought I'd be useful getting an exercise bike for the house. Wasn't sure I'd use it all that much so I just went for a relatively inexpensive one, a Reebok Z9. It's a bit plasticy compared to some of the really expensive ones, but it does the job and was £180 which didn't seem too bad when I was looking around.
It has various modes and programs and nice enough display screen. Tell you things like your pulse, stuff like that. Some assembly was required but it was very simple, just a few allen bolts, took about 10-15 minutes I guess.
I'm not very motivated to sit on an exercise bike, so I put it by the TV so I could watch TV while pedalling. The distraction probably means that I don't work as hard but it keeps me going. I'd watch those TV shows anyway so I suppose I might as well be pedalling while doing it!