Script your development environment
No, really. It can save you lots of time. Everyone who is doing software development for a at least 2 or 3 years probably went through same installation process more than 3 or more times. Installing same packages and configuring them many times is no fun at all.
Of course, not everyone is not doing it the same way and we all have different requirements. But if you're working with a full stack web development environment like me, than you need to install at least one database, one of languages (Ruby, Java, PHP, Python, ...) and other tools like Node.js, Vim, git, ...
Vagrant can be your savior.
Don't stop just there. One virtual machine for all your projects isn't enough. There is possibility that not even one project of yours has exactly the same requirements. This is where Vagrant and Puppet can make your life better.
When you have a script for creating your environment, you can share it with your coworkers (good option is via git repository) so that everyone is using same environment. Puppet will install everything you/they need within a first run.
Scripting my development environment has already saved me a lot of troubles and time although I'm not using it for a long time.
I'm using one for my Ruby on Rails development. You can check it out here and fork it so it will suit your needs. https://github.com/zigomir/rvdb