Product review (5 stars): A cheap 5 minute fix, and saved another $200 Service Call!
When my dryer started making a horrible screeching sound I did a quick internet search and then took off the front panel of the dryer to find that these two little "glides" were worn out.  Only 5 year old dryer, but I guess they don't make 'em like they used too.
1 minute to install and 4 minutes to replace the front panel and I saved yet another $200 service repair call.