Cloud computingand storage is secure if you use Amazon and few other "Tech" kind of services. Not so sure about the cheaper cloud storage places.

Amazon EC2 service is good
IBM Cloud storage service is good
HP cloud storage service is good

But they all want real money!

And for more general storage check this site out
http://www.thetop10bestonlinebackup.com/cloud-storage

I've heard good things about drop box and hear quite a bit about carbonite. Never used them so can't tell you if its super good or not.