I need a 20 GB USB stick

Now that I've had the chance to install Vista and Office 2007 onto several virtual machine instances (mostly under VMware Workstation), I can see that the virtual images truly take quite a lot of disk space.

A basic virtual image of a Windows Vista Ultimate installation takes about 6 gigabytes of disk space, and about 2.8 GB in zipped format. Install Office 2007 on top of that, and you end with about a 12 GB virtual image, which zips back to little less than 6 GB. Wow. A DVD isn't enough anymore, nor are any of my USB sticks. How much did a 20 GB USB stick cost, again?