That is the GREATEST thing, to clep classes. So far I've done Human Growth and Dev, and Sociology in the past six weeks. It saved me several hundred dollars and a LOT of time sitting in class and driving back and forth. I picked up 6 credits so easily.
If you have prereq's like these to complete, and you do well learning on your own with study materials, you should check into whether your program allows clep exams, and where you can take them. The best part for me, is this Sociology class is worth an extra point on my nursing application, which is due now. I feel pretty comfortable I'll make it into the January cut with just that one extra point I didn't expect to have it just two weeks ago. VERY, very excited!