Software or something like it

Hello Fantastic People!
I'm planning to create a website where people can create some sort of bulletin. It's something like creating your own mini website just by filling up a form and everything will be in place. Images, Headers..etc. Is there such a software that I can use to place on the net so people can do that?? One great example is this site from weddingorchid.com. That's exactly what I want to achieve...