Product review (5 stars): Cheapest on the web, pretty fast shipping.
All of a sudden my dryer stopped working.  It still got hot, but the clothes were still wet.  Pulled the covers off and saw the belt had snapped.  Sears and Homedepot had it for about $30 shipped, so for 1/3 of what they charge this is a great piece. The rubber seemed pretty flexible, and it seems like a quality part.

Just remember, while you're in there replacing the belt, remember to clean out the vent, and the inside of your dryer.  A lot of lint can accumulate everywhere which is a tremendous fire hazard, so do yourself a favor and start cleaning.

Also, if you need help replacing the belt, there is a great video on youtube.  Just search Y312959 replacement and there are some detailed instructional videos.