Cavalry 1TB Dual Interface USB 2.0 & eSATA External Hard Drive - CAXE3701T0 - Buy.com
Cavalry USB/eSata external disk good for backups or with the eSata interface, removable full speed storage. $199 with a $20 MIR. New google checkout users get an extra $10 off for their first purchase. Existing google checkout users may be eligible for a $25 off promo. Supposedly they send an email out advising of the promo but many seem to have opted out of receiving the email. But if you qualify its still there.
If you've used google checkout and want to see if you get the $25, add the item to your cart, click on the google checkout button, and log in to your google account. The coupon will then show...or not.
Make sure you select free shipping. Tax in many states applies.
This has a Western Digital 1TB GreenPower drive in it, which usually sells for $199ish without an external enclosure wrapped around it. You can pull the drive and use it inside any machine with a sata interface inside.
To make an existing desktop computer eSata capable, all you need is a small cheap bracket that slips in the back and has a cable that runs to one of the sata connectors on your motherboard. Usually costs <$10 and takes just a few minutes to install for someone familiar with opening up computers and plugging in expansion cards or memory.
Heres what one looks like...this one is out of stock and the cable looks too dang short, but it'll give you the idea. Once this is in and you're using the drive in esata mode, its as fast as an internal drive.
WiebeTech eSATA to SATA Cable with Bulkhead Bracket - CABLE-45 - Buy.com
Some desktops and laptops of newer vintage have esata built right in.