A couple weeks ago I bought a 500 GB Western Digital Passport USB Drive for $150 from the WD store. A co worker recently got a 160gb drive for around $50. These are 2.5" drives. If you want a larger drive that stays on your desk, the prices are incredibly cheap.

You can also just replace the drive in your computer with a new larger one. Slickdeals just posted a 320gb drive for $57 AR.

We generate around 20gb of vacation photos and videos per year and it's accelerating.

How old is your computer if 50GB would provide a backup and room to spare?