If you have a Google account you can now store up to 1 GB of files in Google Docs. So rather than E-mailing a photo or video to yourself just to move it from computer to another you can just upload to Google Docs and access it from anywhere. There’s a file size limit of 250 MB, but if you regularly move files larger than that you probably already have a system in place.
Extra storage is cheap too. You can buy more space for 25¢ per GB per year. For example you could keep 100 GB online for $25 a year, which makes this a reasonable backup service too. You can read more details on the Google Docs Blog.
This isn’t a new concept, but it certainly makes it easier for non-technical people since there’s nothing to install. I’ve been using a service called DropBox for about a year now. Free accounts are available that store up to 2 GB. It’s dead easy, but you do have to install an application. There are other similar services, but DropBox has always worked for me so I’ve not tried the others.