Sugarsync allows you to sync your data between your iPhone and your computer. You can share MP3 music files, pictures, movies, etc. One of the advantages that Sugarsync provides over the others is that Sugarsync offers to store sync’ed files offline on its own servers. After a 45 day free trial - 10 GB of storage is $24.99 while the more realistic 60 GB plan is $99 per year. Clients are available for Windows Mobile, Blackberry and now iPhone 2.x.