For those that are looking at supplements and are seeing a lot more pre-workout drinks or intraworkout drinks with beta-alanine, this may be a good place for you to look to see what it is that you are taking. This is not an end-all source as it does not cite it's studies but it does have alot of good general knowledge on pH, ATP and glycogen production of H+, and carnosine buffering.
http://www.betaalanine.info/Again, take this all with a grain of salt as it doesn't directly mention who's paying for this information (although I'll bet its Athletic Edge or a subsidiary of them). Either way though, much of it is useful information to help beef up your supplement knowledge.