I use the 2" wide industrial velcro tape. The car mat I used worked very well, as the pointy things on the bottom 'dug' into the carpet. But I also needed to have a short wooden foot stool under the table and the one I had was a little long and got in the way of the car mat. So, I put the velcro on the bottom of the pedal and placed the loop section on the carpet. It sticks and never moves! I have pulled the hook and loops apart to vacuum the floor. Then press back together. Already had it on hand for other household projects so was no expense to my sewing and quilting.
http://www.amazon.com/Velcro-Industr.../dp/B00006RSP1