User Profile Image

How do you change the user profile image (the one in the top right of the menu bar)?

NOTE: I haven’t installed any of the demo content, the tournaments plugin and have team wars and tournaments turned off in the theme options. When I click on my name I can only see create team, create tournament, logout options.

I don’t particularly need Arcane for tournaments etc (and don’t want to bloat wordpress with any unnecessary plugins) but would like a nice profile image to show up in my blog posts/comments etc.

What is the most efficient way of adding a profile image?

Thanks.