I need a forum for a group of people, and I wanted to know if anyone had a good suggestion for a free one that was fairly customizeable and ad-free. I had one in high school, but forgot what the address was. Any suggestions?

The only one that comes to my mind now is phpBB.

I like the way it looks, but you have to download software, which I can't do from here.

we use www.forumer.com wich is free but has googleads. Don't know if that's enough for you.

Umm, SMF is the way to go. http://www.simplemachines.org

Why? Well, it blows all the others out of the water, and the community (which includes me) is always willing to help you rip apart and customize it to your needs.

I'll help you personally if you need it.