Recently, I've talked to a few surveyors about sharing files with clients and vice-versa. This morning, I stumbled on this deal at AppSumo where you can get 10GB of online storage for life for $25. I'm not affiliated with them in any way and I don't make any money from them, I just thought some surveyors here might find it useful.
http://www.appsumo.com/lets-crate-lifetime-file-sharing-promo/
The deal expires in a few days.
Dropbox offers 3 or 4 GB free. Worth looking into. Not really intended to share with other people, but it works for that too.
www.box.net is offering 50Gb for iOS users who install the app and sign up for an account.
All of these deals are great, until they're not so great anymore. I'll bet none of them guarantee continuation of service, and most if not all probably don't guarantee redundancy, either. I can see using any of them as long as you don't really need the data, but when it comes to mission-critical cloud storage, you pretty much get what you pay for.
I use Amazon S3, and am satisfied with service and pricing. (I'm also assuming they've resolved their redundancy problem.)
Google, Yahoo, and many others have several gigs of free storage.
Microsoft's Sharepoint has the most power and storage; but I always
keep looking for more.