LOL. Good luck. I hate bar crawls, 'cause when everyone's getting ready to go to the next place, I'm just getting comfy. I just tell them I'll meet up with them later, which never happens.
I went on a pub walk the first time I was in London and felt the same way. The guy who lead it could freakin' put away some suds! I was a VERY serious drinker and his deal was that you could have as much beer as you could drink before he finished his beer and he didn't start talking until everybody in the group had a beer. He would talk about the pub, etc... for a few and then just pound it. As he got drunker, I got more beer. At the end me, a buddy, and him were the only ones left out of about 25.....it was a helluva lot of fun.