Sometimes when I'm browsing PMC I'd love to make it a bit more personal. I think themes, or 'custom themes' would be a great way to do this.

This would involve being able to change the dirt background and/or the animated background with your own image, this would show up only for you and allow for the site to be more personal.

I feel this could be done with little to no impact on the server side and we could just add a link to an external image which will be loaded as the background (if available).

For inspiration I would look at how twitter allows you to select a background on the web version which acts as the site background when browsing the site.

This would also allow for people to share their own art work for people to use as their 'custom theme' for the site.