Get a set of hand weights and a copy of Jillian Michaels 30 Day Shred. It's way cheaper than a gym membership, takes up so much less space than a big machine, and it works. I lost a good inch off my stomach after doing the shred everyday for a month.

Also, go to the pound/shelter and rescue a dog. Then go running with the dog 3 times a day. It works for me!