If you find yourself collaborating and sharing files with a small team, check out DropBox.com.
Dropbox is a terrific application and web service that syncs a shared folder of files over the internet to multiple computers. After you install the application on several computers (using the same account), it creates a synced Dropbox folder on each hard drive. Any file you put inside that folder will be synced and available on each computer or through the Dropbox web interface.
Dropbox works on both Mac and Windows. You can get started with 2GB of shared space for free. Or upgrade to 50GB for $9.95/month or 100GB for $19.95.
Source: We use a free 2GB Dropbox account at CreativeTechs for sharing and working on a variety of classroom materials, including the small weekly class icons that we use to promote each week’s class schedule. It’s a handy tool.