Sigma 10-20mm on sale for $399 from Dell Home

That's assuming you have the 20% off coupon. If not, you can buy one from eBay for under $10. It's a pretty solid deal. You can get another 3% off if you use Fatwallet's FatCash program.

It's a really good lens for the price. Works on Nikon DSLR's and most of the consumer level Canon's as well, assuming you select the right one.