DocFetcher

DocFetcher is a desktop search application: It allows you to quickly access documents on your computer by typing keywords. – You can think of it as Google for your local document repository. The application is available for Windows and Linux/GTK.

Gladinet Cloud Desktop

Gladinet Cloud Desktop mounts cloud storage as local folders* and integrates online applications (Amazon S3, Google Docs, Google Picasa, Box.net, EMC Atmos Online, FTP, WebDav, and more …) with the local desktop.
It is a personal cloud agent, an open online backup platform, and a desktop delivery agent for cloud service providers.

http://www.gladinet.com/