You can sit them on the top of your water heater until they sprout, then move them under the lights. Cheap heat source.

I have had good success using heating pads found at the thrift store under the seed flats. Just experiment with temp. settings ahead of time so as not to overheat them. Low setting is usually enough, and sometmes it helps to put an old towel or something between the heating pad and the flat.

Re:"any cheap suggestions for a heating mat for my starts?"

I use a water bed heater. I think it works much better as a plant heater than the units we see in garden catalogues and stores.

A water bed heater is is a flat, waterproof mat. It's lightweight, flexible, and easy to roll up when not in use. It is meant to lie on top of a waterbed and heat the gallons of water inside the bed's bladder. So it's tough, made to last a long time, even with constant use.

My water bed heater has an accurate thermostat with a wide range of temperature settings. Those pricey plant heaters usually have only one temp setting, and the thermostat just turns it on or off.

The water bed heater is also about twice as long as a plant heater. Although I can fit a few flats on it, I usually like to germinate a whole load of seeds together. I group the seeds on damp paper towels, label them, and place them inside baggies. Then I lay them down along the heating mat, in layers if I have lots of baggies, then place a blanket over top to keep the heat in. I set the temp to suit the seeds. I get very good results this way -- fast germination and good rates.

Where to get 'em....

Water bed heaters often outlive the waterbed bladder, so there are plenty around. You can usually find them stuck away in some dark corner, with the rest of the this-must-be-good-for-something stuff. Most folks are glad to be relieved of theirs and will give it away for such a good cause as yours, so ask around.

If you have no luck with friendly donations, try looking for them at yard sales or listed in bargain hunters. Free is best, but you should never have to go higher than cheap.

If you want to warm a lot of flats together, you'll need to find a few heaters. Another idea I've been tempted to try is to pick up a used water bed frame and bladder, too. I'm thinking that one heated bed could hold a lot of flats! Then I start thinking that one heated bed with a hole in it could flood a lot of floor . . . which is how I came to own my orphaned water bed heater in the first place! This is also, I'm guessing, why so many people have these heaters sitting in their basement, just waiting for you (or me) to come by and put it to good use.

Go for it! And if you do, I'd love to know how it works for you.

Star-Tide

I have found, the must frugal way to start your seeds is to use the Winter Sowing method. There is a forum dedicated to this. No heat mats or lights required! No damp-off either :). Check it out - there are many, many frugal gardeners over there that offer great ideas on using recycled containers, too. The main cost will be good potting soil (which you'd buy to make your flats anyway), some duct tape and plastic to cover your pots. There is a really great FAQ at the top of the board you can scan through to get an idea of the way to do it. The group is also very helpful with questions you'll have. I tried it my first time last winter and can't tell you how many hundreds of plants I grew. I did the indoor method for years - will never go back to it now! Very friendly place to learn...check it out and Good luck!

I'm sorry,I've been in the hospital for the last 10 days and couldn't thank all of you for the great imput.There are some really good suggestions here.I'm out of commission for a while.Maybe next year.Thank you all.