iPhone: Previously mentioned personal cloud data searching tool Greplin has released an app for the iPhone that sifts through data in your various online accounts as you type. If you have a web-based Greplin account already, you just need to sign in and everything is ready to go one your phone.
The iPhone app works much like the site, as you can add any Greplin-supported sources directly from the settings. These include Gmail, Facebook, Dropbox, LinkedIn, Google Reader and a bunch more. Once added you may need to give Greplin some time to index, but after that you'll be able to search through all your cloud data as you type. If you're having trouble finding anything on the go, it's a great free app to have. Like with the Greplin service, it's free to use, but premium service upgrades are available to give you the ability to search even more services like Google Apps, Campfire, Basecamp and Salesforce.
Greplin [iTunes App Store]