stevey said:
start off with phpbb and see how it goes, as your forum grows you can always upgrade to VB if you wanted
I'm with Stevey on this one. Everyone's so quick to chip in with vB, but spending $160 on a forum that might not even take off, (let's face it, most don't), that's a waste of money. I have at least a dozen forums online, and I'm not about to chuck a grand or two at them unless it pays off!
PhpBB is more than adequate for a small-to-mid sized forum, and if you forum starts earning you more than $160 per year, then you can splash out on vB licenses.
Just my $0.02...