What version control system do you use for web apps?

[eluser]ejangi[/eluser]
I've seen git mentioned more and more online these days, but personally I (also) vouch for using EclipsePHP with the subclipse plugin.
You could also use something like capistrano to deploy straight from the SVN repository (and roll-forward/back with a simple terminal command).

The only thing you will probably need to change from local to live is your config, which is thankfully all kept in the one spot. But, what I do locally is setup everything exactly like the live (database names, usernames, passwords), so that all I have to change between local and live is the base_url.