I really like this diy heat table for starting seeds. I know warming the soil helps the seeds get started faster. Very nice tutorial from Door garden with plenty of pictures to show how they made it. You can also use it to heat a pets bed. Don’t you just love ideas that have multi uses.
Home Made Bottom Heat for Seed Starting (or pet bed)
http://doorgarden.com/02/home-made-bottom-heat-seed-starting