This looks really promising: Four Reasons Textbook Costs Will Drop (from US News & World Report).
I thought I was doing well by getting used textbooks through Amazon, but there are some really interesting options developing– e-textbooks and textbook rental.
Also, I’m thrilled to see lawmakers doing something to help students! (Although the cynical side of me wonders who will benefit from this– this will decrease the amount of loan money that may go into default.)
Still, good news!

I was sent to the site http://www.bigword.com you put in your ISBN number and it searches all sources, including rentals, to show you your cheapest options.
@ writewoman: I had great luck with regular old Amazon this past semester, but I’ll check out all the options. Thanks!