[akeating]

Buying one of these http://www.concept2.com/indoor-rowers/model-d worked for me. Full body workout I can do at home.

[SketchySeaBeast]

I love rowing for conditioning. It's up there with prowler/sled for puke factor if that's what you're going for, and it's great for general cardio if you don't like uncontrollable body tremors.

[overcast]

I've got the same Concept rower. Rowing is the only exercise that will completely annihilate you every single time.