Too many “CLOUDS” in the sky!
I will not be doing a review or comparison here as there must be thousand of them out there. My gut feeling is that at the end I’ll be using Dropbox and Skydrive.
The background upload speed of these services are more or less the same, dropbox’s app is more polished as you can set sync’ing bandwidth. Both Dropbox and Skydrive have a file size limit of 300Mb if you upload via browser. For Google Drive I have tried uploading via browser a 2Gb file and the speed (Wifi) is much faster.