I'm pretty sure there is not a specific mobile version of the forum, as in wap.barrowdowns.com, and I seriously doubt if there will be in the future. (to my knowledge, and I run a forum) vBulletin boards don't have an official mobile version of their software, and though I imagine a mobile-friendly customization could be found from a third party, I've never seen a forum like this one optimized for such devices. I don't think it would be high on the agenda for the owner of this forum, unless there was a large demand for it, and sorry to say, I don't think there is. That's tough for you.
BUT, that doesn't mean you can't access the forums (forum.barrowdowns.com) on your mobile device. I tried it just now on my non-blackberry cell phone and it worked...it takes a lot of scrolling, but I posted in this very thread from my phone. I imagine the bigger screen on a blackberry will make the experience much nicer. Have you tried it yet? Good luck!
TM, you're right, most new cell phones can access most (not all!) webages, with varying degrees of usability. Some sites have specific mobile versions simplified for a phone. m.ebay.com is an example.