Newegg has a pretty good deal on a 1.5TB external hard drive. The Seagate FreeAgent costs $119, features a 7200 rpm drive, connects via USB, and includes free shipping (the deal ends today). Reviews have been mixed as this drive apparently had some problems early on, although it appears that the kinks have been worked out thanks to new firmware.

Seagate FreeAgent [Newegg.com]