I rebuilt valgrind tonight against glibc 2.7, so you may see improved performance using this tool with your pacman debugging and memleak-finding expeditions.
I'm mainly letting you all know this because Xavier asked me to write up something on how I use valgrind with pacman. I threw up a short little article on my blog (http://toofishes.net/blog/) to help people get started, the actual article is here: http://toofishes.net/blog/using-valgrind-c-programming/
If you guys have any questions in the future about how I do stuff, whether its coding, algorithms, tools I use, etc. *please* feel free to ask and I will try to answer, either privately or publicly.
P.S. I'm already number 5 on Google (OK, I had to cheat a bit with the search terms). :) http://www.google.com/search?source=ig&hl=en&rlz=&q=valgrind+c