If you are constantly moving files between computers via thumb drives, or by emailing them to yourself, consider using Dropbox.com, which serves as a central repository for personal documents.
The first thing you do is create an account on the site, and then download Dropbox onto each computer that you use. A Dropbox folder is created where you decide to place it. If you are working on a file that you will need at work, simply drop it into your home PC's drop box and it will be in your work PC's Dropbox folder.
Dropbox is available for Windows, Mac and Linux. Mobile apps include iPhone, iPad, and Android (Blackberry is apparently in the works).