USB or firewire...

Are these available cheaply anywhere? All look really expensive...

Good old eBay.

Been keeping an eye on 2.5" caddys on there for a while as I want a 250/320gb drive myself.

http://cgi.ebay.co.uk/2-5-SATA-IDE-to-USB-eSATA-HDD-External-Enclosure-Caddy_W0QQitemZ290234395479QQihZ019QQcategoryZ86758QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Has USB and eSATA which, if your motherboard has makes it as fast as basically plugging the drive into your motherboard.  It can also take IDE and SATA hard drives so you can use it with whatever youve got lying around or go buy a nice new shiney drive.  All this for a bargin tastic £11.99 + 3.99 shipping.