Note Peltier devices are the heart of those 12volt small fridges you power from
your car cigarette lighter.

Put electricity in - you get a temperature differential between the two sides.

The peltier effect materials are engineered for a certain temperature range - the consumer grade stuff that's easy and relatively inexpensive to purchase will not take the high temperatures needed for stovetop use directly - there has to be a disconnect like the bi-metal strip. I've seen much higher temp peltier devices on the web for 3-5x the going rate of the common ones.

I spent a few days back east w/ my Parents and guess what, Dad got one of the two-blade 100cfm fans as a gift. He also got a digital IR thermometer w/ the laser pointer built in so I scanned the temps on the fan. The fan sat on a steel plate fireplace insert stove top - the center would heat to ~500 easily but the fan has to have cooler air to draw in to the top fins for best results so it's kept to the side of the stove top.
So with the fan base set on stovetop at ~400 the bi-metal strip would have it tilted back about 2-3mm & the aluminum fan frame would register around ~200 just below the peltier module and ~180 just above. The usual temperature drop was around ~18F but at start-up the fan would be moving with as little as 2~F difference. When it was really spinning the top fins could read between ~90 and ~135. I didn't take notes so the figures are from memory but it explains the heat flow a little better...

On a side note when the chineese and others devoloped metal pins they
began electro acupuncture era as the temperature difference in the
shaft to the different metal wrapped as handle  up in the air creates a
pontential with an air ion return path that is on same scale as the
firing of nerves and cellular metabolisom which is similar to the
currents of corrision or in our battery cells.

Space craft to industry use thermopiles to recover power from waste heat.

http://allelectronics.com/

For about 15$ they have a whole block of them.  Don't know what voltage it will put out, so don't know what kind of fan to put with it.  Make sure you put it so that the fan is pulling cooler air over the heat sink, otherwise you might melt the Peltier elements.  

http://www.thermonamic.com/Pspec.html

http://www.varmaraf.is/engl/prod.htm

http://www.powerchips.gi/

http://www.dts-generator.com/

http://www.hi-z.com/

It is not fool proof. They fry regularly on red hot stoves.

Most I see are about an 8" blade.

I know of another made mostly of wood that is a Sterling. Wish I had a pic.