I got two. One's a Western Digital "elements" SE 500 GB for around $80 and works great. Not the fastest thing in the world but very adequate. Also got a Western Digital elements SE 1 TB external drive for just under $100 plus shipping. Got it through "tech deals" on the net.

I've never had a Western Digital drive fail on me in the 15 years ive been using them. Lacie seem nice but i've never bought one (usually too expensive for what you get)

Just my experience though.

I'd stay away from Seagate.

I've had my LaCie Rugged portable for two years. Never had a single problem and I keep my music library on it (w/Firewire, but I have an older Macbook). I have other externals for backup but this one is the dreamiest. FWIW, I have never had any problems with any of those HDs either, which are also LaCie.

I have experience with both LaCie units and Western Digital products.

WD drive units (e.g., the Caviar series) themselves are consistently durable and have lasted me a long time. None have failed me before a warranty expires. But Caviar are 3.5" and beyond your size needs. Have you considered investing a little more for portable durability by buying a solid state drive (SSD)? These are going to be less affected by vibration, shock, and jittering than any magnetic platter unit. The quality on SSDs are now very good, and the prices, while still higher overall compared to magnetic drives, are steadily coming down. Intel and WD are both producing good SSDs.

I also have owned a LaCie NAS unit called the Big Disk ED series. The particular model I owned used Maxtor disks. Unfortunately, the Big Disk series have been notorious for two reasons: faulty circuit/logic boards proprietary to LaCie and for arguably some of the most unhelpful support service whilst under warranty. LaCie's recommendation has been to send a faulty drive to them, and they will replace the drive. They will not recover your contents or transfer the non-defective disks to a replacement enclosure, even if the disks were not physically defective. They do not have an authorized service network which might allow you to speak to the person who might be serving your unit. For now, I would avoid LaCie until they substantially revise the way they work with their existing customers' needs.

Obviously, backup backup backup, but always find an external drive vendor which will stand by their warranty and work faithfully with you, the customer, should their equipment go south. Good luck!

I like the OWC Express 2.5" enclosure. It's not festooned with logos or LEDs, it's about a third the thickness of the LaCie Rugged (also a nice drive), it's fast enough by USB standards, and it's reasonably priced at $20.

On a desktop I prefer Firewire, but the Express is the drive I take with me as portable backup when traveling, and when migrating data from laptops with logic board problems.

OWC currently has a bundle of the Express, a 500 GB/5400 RPM Hitachi drive, and a small set of tools for $80: http://eshop.macsales.com/item/Hitachi/Y0A57915/

There's also a 7200 RPM Seagate version of the same bundle for $100.

The one that's the best deal here: http://dealmac.com/categories/Computer/Storage/Hard-Drives/External-Hard-Drives/472.html

Like right now they have a 750 GB WD for $80. Or a 1 TB for $100. Or a 500 GB for $60. Woooooo.

Check once a day.

Really any name brand portable hard drive will do you fine.

The LaCie Rugged series are pretty great. Very small form-factor, bus-powered (no power adapter needed), and pretty good looking. They're not the cheapest drives around, and I believe they are 3.5" drives, but they're great for tough, portable storage.