need a web 2.0 graffiti wall

I need a web 2.0 style graffiti wall website. Must be as inexpensive as possible. Must understand that there are existing php scripts already in existence. So bidder must know about existing open source scripts. to bring my costs down. Need to be able to post text and images on a website, like graffiti. text and images must link to websites etc. Prefer an admin panel so I can easily add text and images and their links. example: person wants to post a link on the graffiti wall. They send me the details, I post it, OR They post it, taken to paypal payment option, then I approve of disapprove the post, and make it live, or revise and make it live. just like buying tags on tag cloud sites. but using images or text option. email me etc. RELEVANT samples