Zalman NC-2000??
What about the Zalman NC-2000? I've got one and it keeps my 17" Asus G2 nice and cool. With the G2 running at max performance, it'll definitely roast the old chestnuts if you leave it in your lap.
The cooler is lightweight aluminum, USB powered and about as close to silent as you can get without being a passive cooler. The Zalman NC-1000 is identical, just in a slightly smaller package.
http://zalman.com/ENG/product/Product_Read.asp?idx=280 <- NC-2000 Link
http://zalman.com/ENG/product/Product_Read.asp?idx=130 <- NC-1000 Link