I now have 14 GB of cloud synchronised storage: DropBox (2 GB), Google Drive (5 GB) and Microsoft SkyDrive (7 GB). I have another 25 or so GB of music and archival stuff which sadly has to stay on local storage only. As it's read-only my disappointment is bounded.
DropBox is still the best: very, very fast to synchronize between machines and very accurate in keeping track of complex changes.
SkyDrive is also excellent, loading 3.4 GB of video and personal stuff in no time.
The real disappointment is Google Drive. It still hasn't finished uploading a couple of GB of pictures - it seems to trickle feed, in that irritating way which put me off desktop Google. It also keeps dropping the connection. What rubbish.