I've used phpbb for a previous message board project and I've been asked to help in setting up a new one.
The guys who're asking for the community want something like Vbulletin. That say they can't afford it right now but and will move onto Vbulletin over the next few months.
They're particularly interested in running banner ads at the top of the page.
So what message board setup can you recommend that's reasonably easy to make the switch to Vbulletin and can also run banner ads?