Dropbox is an over the air, or "cloud" service. 2GB's free. 50 for 9.00 a month. You drop your file into the dropbox account and either give out the username and password, which I don't recommend, or you provide a link to the file via email, and the receiver goes and downloads it from the cloud.
Pretty easy to do. I think. I utilize it for all my work files so I can access all my music, videos and papers without putting a kb on my iPhone. Haven't used an SD card in a while now. Anything you can download Dropbox to, or access the site from, you have your stuff.