We love Dropbox here at Linux Journal. It's cross-platform, offers a decent free offering and generally "just works". It has some problems though. Dropbox is proprietary. Dropbox stores a copy of your data in its own data repositories. Dropbox is limited in size, especially with its free accounts.

Enter SparkleShare. SparkleShare is an open-source project that allows you to start a Dropbox-like service on your own. It's a very new project and needs time to mature, but the beta is promising. Also, because you run the server yourself, there are no limits to the amount of data you can store. It's also cross-platform and has some of the same sharing features offered by its proprietary brother.

Check out the early stages of SparkleShare at www.sparkleshare.org, and if you're a programmer, consider contributing. I'm excited for a stable alternative to Dropbox that I can host myself.