I use these Silicone liners when I make cookies, bisquits, rolls, chicken or fish. I simply place one onto my baking sheet, place my cookie dough, bisquits or whatever on them and cook accordingly...nothing will stick and my cookies slide right off the sheet without a hitch. I especially like to use them when making dinner rolls. I had a problem with the bottom of the rolls getting too brown but with these liners that never happens and my rolls brown just right, everytime.These liners are supposedly oven and microwave proof to 500 degrees. Personally, I can't imagine why you would need to use them in the microwave but they say you can. On a baking sheet they work wonders though. They can be used over and over and clean up is easy too, simply wipe clean with a little soapy water. I bought mine thru mail order (Carol Wright) but I believe you can also find them in stores. If you do much cooking or baking you should try these liners. They are inexpensive, easy to use and very effective.
Update On May 05, 2008: Having read over this review I see that I listed two different sources. Actually, I think I did buy these liners from Harriet Carter but they are readily available from most mail order companies such as Harriet Carter or Carol Wright. Also, I wanted to be more clear about cost. I paid about $6.00 for one liner.