Have a look at my image upload plugin

[andypooz]

Because we're all so excited about the new custom fields plugins, and because loads of people have been asking for a solution that can allow users to upload a picture into their profile, I've created something that makes use of the new custom fields functionality. It ajax-uploads the image, and has all the usual file size/image dimensions /format restrictions.
I'll submit it to the JED soon, but as that could be a lengthy wait, if anyone wants to have a peek and let me know how you get on:
http://www.netamity.com/image-upload-plugin

Cheers
Andy