I want to

Get your online storage space - humyo.com

with humyo.com. Up to 10GB storage, free forever. 5GB for media, and another 5GB for non media. There's a commercial version as well at £46.99, though at that price I'd think about investing in an external hard drive, unless off site backups are really important to you.

PutPlace

PutPlace gathers all your valuable digital stuff — photos, documents, email, music, videos — from all your PCs and laptops. It backs up everything, securely stores it, and organises it all so you can find or share your files from anywhere.

Dropbox - Home - Secure backup, sync and sharing made easy.

Dropbox.. is now public, so you don't need an invitation code. It's a piece of software that you download which allows you to backup files as you change them. I've not tried it myself, but it does look very impressive.