Great price on this drive. I've just bought one for my XBOX Slim. 250GB is the largest capacity drive you can currently use on it.
Have a look here on how to prepare it for the XBOX 360 Slim.http://digiex.net/computing-section/guides-tutorials/xbox-360-guides/3152-xbox-360-how-hack-250gb-sata-drive-work-xbox-360-xbox-360-slim.html
Cheapest i could find and it includes Super Saver delivery!
-edit- After reading comments posted about this deal, I should clarify that this deal can be bettered in terms of cost per GB but if the purpose of this drive is to add to an XBOX 360 where 250GB is the limit and also in terms of drive compatibility, this deal should prove useful. Perhaps I should have titled the deal a little more carefully but rather than doing that now, I'm just adding this paragraph.