The most common request in this forum is for developers looking for free or cheap artwork. Given that this forum mostly comprises developers its not always the best place to look for artists. Here are some websites that have been recommended for finding people:

• http://www.deviantart.com
• http://www.cgsociety.org/
• http://polycount.com
• http://conceptart.org
• http://forums.indiegamer.com/forumdisplay.php?f=20 
• http://www.guru.com (general work for hire place)
• Cryovat says "a lot of webcomic artists offer commissions, often for very cheap. For character portraits, early concept art, etc, this can be a nice place to look."

If you have any other places please reply to this thread and we will add them to the main post.

This DOESN'T mean that you cannot post requests for artists in the XNA forums, just a suggestion that you may get more responses elsewhere. Please continue to post your requests in these forums.