Storage: 2 GB Free, with Personal and Enterprise Plans Available
Desktop Support: PCs with Windows XP or greater, Mac 10.5 or later, and the more popular Linux distributions
Browser Support: Most modern Web browsers
Mobile Clients: iPhone and iPad with iOS 4, Android 2 or later, Blackberry 4 or later
The helpful mobile apps on iOS and Android allow easy access to your data. If a file is in a backup set, you can get to it from practically anywhere. You can even back up files that are on your mobile device.
Sharing works via a concept called "Share Rooms" and gives you control over what files you share and with whom.
With full file versioning and the combining of sync, sharing, and backup into one service, SpiderOak deserves a serious look for those whose top concern is security. Bottom Line: SpiderOak offers everything that Dropbox does, but with better service offerings and benefits, plus a superior price point.
You're not up to speed on Dropbox? Click through to the next page for a refresher.