You don't actually need to sign up with picnik. You can just upload your photos there.
I'm sorry if that was understood, just thought I'd throw it in there.
@missfreako picnik has free registration which allows you access to a large number of their features, or for small fee (I think US $20) you will have a premium membership that gives you several really nice additional tools to play with. No, it is not required to actually register, but by registering the site hold your last 5 photos (more with premium)- plus it's free and easy :D
I'm sorry if that was understood, just thought I'd throw it in there.
There are a bunch of free editing tools you can use online.