I cycle to work and back 5 days a week, about 25 mins each way. Tend to go for a half hour walk at lunchtime, to the shops and back. 2-4 days a week I'll do another half hour on the cross trainer when I get home from work (or will start to do again once the blummin thing has been repaired). 2 or 3 days a week I'll also do about 20 mins light weights and various stomach crunch thingies, in front of The Daily Show. I don't tend to do much at weekends, maybe an hour or two's walk if the weather is nice.
That sounds like an awful lot, but there are many days where I don't do anything but the cycle to work. The common theme to all my exercise is that I have to get something else into the bargain - shopping, avoiding crowded buses, listening to podcasts while cross training, or watching the telly. I simply CANNOT do exercise for its own sake, so I've worked out ways to sweeten the deal and it makes it a lot easier to keep it up!