I set up a Yahoo Pipe to aggregate the various phrases for BbWorld (bbworld, bbworld11, devcon11, bbcollab2011). It also filters out entries with the word "blackberry" (as that's the other common #bbworld).
http://pipes.yahoo.com/pipes/pipe.info?_id=bd193c390fbb87682b90e69a22559f7b
It is a bit poky to get going as it has to ask search.twitter.com for data. If there's a more efficient way to aggregate multiple twitter feeds, please do tell!
