Today Buy.com has a 4GB Memory Stick for $19.99 with free shipping.
Smart tip: Back up everything! These disks are invaluable. Remember when you see memory disks on clearance, etc. it doesn't matter if they fit a camera, they will hold your data. All you need is an MS or MMC or media port on your PC. Most PCs take all of them.
You can make your PC run MUCH faster by moving photos to disks or burning them to CDs.