Maplin have a handy converter for sale just now for £24.99:

IDE / SATA to USB 2.0

  • Connect your IDE or SATA hard drives externally via a USB port
  • Allows you to connect 2.5 inch, 3.5 inch IDE and SATA hard drives
  • Includes 3.5 inch to 2.5 inch adaptor, SATA power and data cables
  • Complete with PSU
  • Compliant with USB 2.0 transfer

Handy for those days that your PC or laptop goes down and you really need to get data off it, asap.

I’d find that particularly useful for 2.5″ laptop drives.