I'm loving it: suspension training.

I think I've mentioned that we have a suspension training system (the Human Trainer). If not, now you know. (You should also know that I am not in any way affiliated with the product, have received no endorsements/remuneration/etc.) I like it, and I think it's helped me train without risk of further injury (because I'm not in a static position) and it's incredibly easy to set-up/take-down. We have ours attached to the garage door:

(I usually move the trashcan and broom out of the way)

My liking passed into love when I started incorporating suspended crunches (here's a few sample exercises from the Human Trainer website), twists and pikes. It's the hardest thing I've done in a while and it's the only exercise that requires a full minute to recover from. The results are absolutely fantastic: after two workouts I looked at my abs (which are still not ready for any type of picture) and noticed a difference. I'm starting to believe that I might be able to reveal my abs without fear (not that I really want to, but I want to be able to should I want to). My shoulders, which are incorporated into the movements, are also looking fantastic, so fantastic that I only do one other shoulder exercise during my routine (a goblet squat to shoulder press with a 20-pound kettlebell).

Of course the Human Trainer isn't the only suspension training system out there. The TRX is popular (I have no affiliation with this product) among others (which I also am not affiliated with). If you want something low-tech and portable this type of thing might be what you're looking for. Be sure to do some ab moves; you won't regret it (at least after the soreness goes away). If you're a fitness nutso like me you might even call it love:)