overGrive - Complete Google Drive desktop client for Linux
ExpanDrive - ExpanDrive is a fast network drive and browser for cloud storage.
Syncdocs - Syncdocs syncs folders between all your PCs and Google Docs.
ifttt - IFTTT puts the internet to work for you. Create simple connections between the products you use every day.
drive-cli - Google Drive client for the commandline
FileCloud - FileCloud is an enterprise file share, sync and mobile access solution.