This weekend, Fry's is selling the Western Digital 2.5" 250GB ATA drive for $69.99. This is a fantastic deal if you're looking to upgrade the drive in your Apple TV. (The online price is a bit higher at $74). 
Be careful to make sure you get the ATA drive - my local Fry's had the ATA drives right next to the SATA drives. The ATA drive is marked EIDE.
Be careful to make sure you get the ATA drive - my local Fry's had the ATA drives right next to the SATA drives. The ATA drive is marked EIDE.