The Akitio SK-3501 Super-S3 hard drive enclosure is a one stop shop for your extra storage needs. This 4-port enclosure is speedy, stackable, capable of handling drives up to 3TB and works with Mac OS 10.2 and up.
I am a huge consumer of hard drive space. Between graphic design, web projects, print, branding, UX and video editing, hard drives fill up as fast as I can buy them. I have found it a bit easier to buy JUST the HD and swap it out of an enclosure as I fill it up. The Super-S3 is perfect for just that plus it offers 4 different connection ports (2 Firewire 800, 1 eSATA & 1 USB 3.0). It’s speedy, keeps the drive cool without needing a fan and stacks with other Super-S3′s really nicely. It retails for about $100 from Amazon.com. (Just remember that you need to buy the drive too)

I don’t have a USB 3.0 or eSATA port on my MBP but the FW800 and USB 2.0 worked great (and fast). I definitely recommend this drive as an addition to your storage needs however I can’t really speak on the subject of it’s longevity as I’ve only had it for a month but it’s worked like a charm 100% of that time for me.