I bought an Icy Box from Scan last month. It's an excellent range of hard disk enclosures made by RaidSonic. The casing is a bit flimsy. Really, it's just two sides of aluminum that sandwich together the hard disk and circuit board. Wire mesh surrounds this sandwich and allows a large amount of air cooling. There's no fan so it's nice and quiet. That's about it.
What I like best is that the version I have (IB-351-StUS-B) supports USB 2.0 and SATA external connections. SATA is about three times faster than USB. The box even came with the SATA PCI extension...