SteveStrummerUK
sharke
I don't know about changing the imgur background, but I do know there's no need to open an account to use it. Unless of course you're looking for a place to store your photos, comment on other people's etc.
Not for storing them per se, just somewhere to upload them and then get a link to be able to embed/include them elsewhere... mostly here.
Yep, no need to have an imgur account for that. You can just go straight to imgur and upload an image and it will give you a link.