Lots of great suggestions here, also check out Tim Ferriss's "Perfect Posterior" article on how to build a T-handle - which is a much cheaper kettlebell substitute.
One thing I would throw in just because; burpees. Do anywhere from 15 to 100 burpees four to seven days a week, in one set. Great conditioning tool, can be done anywhere, nobody does them because they're hard as hell.
One thing I would throw in just because; burpees. Do anywhere from 15 to 100 burpees four to seven days a week, in one set. Great conditioning tool, can be done anywhere, nobody does them because they're hard as hell.