This deal has ended.
Buy.com has the Compaq Presario CQ50-110US Notebook for $579.95. This has a 15.4" widescreen display, 2.0GHz AMD Turion dual-core processor, 3GB memory, 200GB hard drive, double-layer DVD / CD burner, media card reader, and Windows Vista Home Premium. If you're a new Buy.com user, activate this $10 off $200 coupon. Shipping is free and there is no sales tax (except CA, MA, MD, NY, TN), though you'll have to pay for expedited shipping to receive it by Christmas.