+1 on the value of using a foam roller! When I use mine consistently---meaning 4x to 5x a week for about 15 minutes each time, it makes an amazing difference in how I feel. The roller works wonders on trigger points that might otherwise be tough to get at using your fist or a tennis ball. My lower back, glutes, IT band, quads all benefit. As others have said, the roller will probably hurt at first, but the tenderness will lessen with regular use.

If you're interested, you might want to take a look at Clair Davies' trigger point self-therapy book. Chockful of good info on referred pain and trigger points. It helped me figure out the source of assorted aches, pains and lack of flexibility.