Having a source control system is a must these days, but I must say that coupling that with a continuous integration (CI) build system is just as important. It's really frustrating to pull the supposedly latest or most recent 'stable' or 'production' version of code from source control...
After using progressive browsers such as Firefox and Safari in my previous employers, imagine my dismay when I realised we were stuck with IE6. One of the things I missed as I had to step back and bear with old IE6 is the absence of the search bar. We're not allowed to upgrade to IE7 nor download...