I've recently found vcs_info being rather slow - and lo and behold, found a nice recipe to make execution of git/hg optional in Misc/vcs_info-examples. I've started using it, and I've rewritten it a bit to make it simpler (less code is good, right? :). Included patch shows my changes (including removing the obvious things, like autoloading vcs_info, etc).

I hope you'll find the included patch useful :)

KT.