I actually did sprints on the rowing machine today, a day after a heavy lifting session. First time I've ever done it but I felt good - not saying I'll be feeling so good tomorrow though...!
I normally do lifting on Monday, Wednesday & Friday. Tuesday & Thursday I normally do a lengthy walk to work but wanted to change things about, so thought I would do rowing sprints on those days for a while, and see how I get on.
So I'll be back tomorrow doing lifting - I'll give it a few weeks then I'll try and get back and comment on how I feel. But I've been reading up on how this works out for other people and on the whole, they seem to have some good results.