In some areas, you can work out for free. Some school gyms or workout rooms are open to the public (at least to families who have children in that district). You can also usually obtain permission to walk or run the track at a school, and many parks have walking paths. Parks are especially nice, because they usually have better scenery. Do you have any free workout or exercise tips?
You can exercise anywhere! You just need a space large enough to fit the full length of your body and you can do push ups. Add another metre or so and you can do lunges. Within that same space you can do crunches, all sorts of abs twisting exercises, jumping jets, leg raises, knee high jumps, on the spot sprints and so on. This is in fact the best way to get some exercise in if you are really busy and don't have time to go to the park. Absolutely free of course. Other free exercise tips I can give are getting a skipping rope. It's excellent for building your cardiovascular system. Skipping ropes are pretty cheap and you should be able to get one from any fitness store. Of course, don't get those the $1-2 types that break easily because they use lousy quality plastic or rubber.