As a freelancer, I keep a hard drive with me to cart around projects and renders.  USB flash drives are great, but sometimes they just aren't enough storage. The Firelite drives are compact and do not use an external power supply. Keep it DOS formatted and you've got a high capacity cross-platform solution that can transport the largest of projects right in your pocket. 

Reading the Amazon reviews, one user states that "It doesn't work with mac laptops", which is inaccurate.  The USB port DOES need to deliver ample power, which some USB ports and hubs do not do.   I use a Belkin USB Hub that works just fine, as well as my little MacBook that also works perfectly with it.  If you have an older model laptop (Mac OS or Windows based) check the specs on the USB port to ensure that it delivers 5V or more to USB devices. Odds are, most modern laptops will, but be careful with smaller unpowered USB hubs.

Summary

Cost: $106 at Amazon

Pros:

• Rock solid
• No external power supply
• 5400 RPM drive
• Small enough to fit in your pocket

Cons:

• Requires powered USB port