Not quite sure how I ran across Fitness Hacks for Geeks but it's a very nice article about some of the options for making it easier to exercise.
I'm lucky enough to live a few blocks away from Mt. Tabor Park. It's notable for being the only extinct volcano within city limits in the US. It's a bit silly to call it a mountain, given that the mountain blew up many thousands of years ago. But the little (I assume) that's left still makes for a challenging walk or run.
I particulary like the references to Dance Dance Revolution as a way to exercise. I've got an iPod but I can listen to music or do things - not both. If you can multitask like that, great.