I've seen Scott's posts about using Dropbox but wanted to share some alternatives which I've mentioned before.
We all know about Dropbox and it remains my favorite, but just as a heads-up, they just sent out an email saying they've upped the maximum limit you can get free from referrals to 16GB.
Box.net as already mentioned allows like 5GB free but if you sign-in using any LG Android phone or tablet between now and the end of the year you'll get 50GB free. But I can invite others using the same domain as my email and they also get 50GB free. So, all I have to do is create accounts like, email@example.com, firstname.lastname@example.org, email@example.com, etc., and each will have 50GB free.
Finally, I really like Amazon S3 because of the control it gives me over my content, especially if you will be sharing it on a website. It's also dirt cheap at about $0.14/GB per month. To upload files you can use the web and upload files individually. I use Transmit 4 (for Macs) and it mounts my S3 storage as a directory/drive so I can simply copy files to it and it's automatically uploaded to my account. I have a script that syncs several directories with my S3 account so it works just like dropbox but better because I'm not limited to just one folder. It's also far more secure than any of the other services. I currently have 28GB on here and it's costs me $4.20/mo.
As for Amazon S3 being better for managing content, I can create a CNAME record to work with my website domain so all I have to type is something like cdn.athleo.net/myfile.txt instead of something like this cdn.athleo.net.s3.amazonaws.com/myfile.txt.