I'm also interested in using Valgrind. Initially i was concerned that it might only support ubuntu, its almost a year old but there is information of how to install it on a beagleboard here: http://changetheworldwithyourpassion.blogspot.com/2009/09/how-to-build-valgrind-for-beagleboard.html
I haven't managed to get the wifi working on my prototype yet, so i'll leave this for some one else to try.