These suggestions are geared towards the Linux/MySQL/Apache/PHP portion of the code-o-sphere.
There are many flavours of source control, like CVS, Perforce, SVN, git and Mercurial. I've used CVS, SVN and git, and my overall favourite is definitely git.
Free hosting of public git repositories, and a great social coding environment can be found on GitHub. I'd highly recommend contributing to some open source projects on GitHub, or creating your own projects, as it's an excellent place to point potential employers to, as they can actually see code you've written.
If you want to host private git repositories, Bitbucket allows you to host an infinite number of private repos for teams of up to 5 users.