guys! i have successfully integrated the flickrRSS plugin and the lightbox2 plugin for wordpress. For wordpress users out there, do check it out at : http://www.weboutsourceit.com . You can find the code there and a demo on the index page. just click on the images. Feel free to leave your comments. Thanks!
The code indicates that they made it themselves or heavily modified something else. I can't find any information on what type of forum it is. I suggest you get invisionboard or PHPBB if you can.