[NicoJuicy]

Just built it with what you already know.. Stack is secundairy to your idea ;-)

You'll scale later when it works.

[paliopolis]

I knew PHP and .NEt but that was some years ago. I will probably need to pick it up again and that's why I was wondering, since I will have to refresh it, should I just look into learning the latest and the greatest that might be helpful or just do a quick brush up and then "cross the bridge" when I get to it :)

[NicoJuicy]

I've also known PHP, i'm mostly in Asp.Net MVC now (it's .Net)

But if you're starting from scratch and aren't using windows, i'd advice ruby on rails.

If you're using windows, choose between Rails 3.2 with Ruby 1.9.2 (bug with Ruby 2.0 on windows :( ) or Asp.Net MVC.

.Net will cost you something to, but just enroll as a startup (BizSpark) to get yourself going.

If you're going to Ruby On Rails, you should consider using Linux and Git all the time for deployment and compatibility though... But it works :-)