Drew,
Unlike this year, we will be flying. We were somewhat familiar with Denver, and very familiar with the Bay Area. We used the light rail in both cities and did not bother with a car when at those conferences. We did not use beerbybart.com, but that is a great resource.
Just did some google searches. It looks like there is a trolley stop not far from the hotel. So far so good. We are not familiar with SD. Some links on the conference page would help us out seeking a beer off the hotel grounds.
Just looked for one, found this link below. Do the locals have more? Will there be a list of other things to see and do using the trolley that are not beer related? This can really help one have mobility without the cost and responsibility of a rent a car.
http://www.sandiegoisbrewing.com/2010/02/san-diego-trolley-and-san-diego-breweries.htmlEdit - If my wife has the social package, info like this will be a big hit for things to do during the day.