In my time with a personal trainer, I was introduced to TRX and love it. It's suspension training; basically two ropes hanging from the wall and you can do an endless amount of exercise on it. Personally, I like that you can do yoga with it!
It was invented in the Navy SEAL's according to their website. It "draws on leading-edge research and best practices from the military, pro sports, and academic institutions..." Next time you find yourself in the gym, see if they have it and try it out (with some supervision at first).