Subversion
I’ve always wanted to get to grips with Source Control Systems, not because I work on code simultaneously with others - but for their ability to keep old versions of sources long after you’ve changed them. CVS (Concurrent Versions System) is the standard tool for this kind of thing - but I always put off learning about it in any great detail because it seemed rather complex.
XCode 1.5 was released recently and one of the new features is support for Subversion. Subversion is widely touted as the sucessor to CVS and has several features that CVS lacks.
Great timing then for O’Reilly’s MacDevCenter to publish an article that wraps up how to set-up your own Subversion repository on Mac OS X.
It’s really more straightforward than I thought - and after a few hours reading the Subversion Book I had a working repository and a rough knowledge of how to use it.
Apple has documention for how to use Subversion in XCode.
Then, once you’ve got the hang of it all - revel in the glory that is SCPlugIn - A framework and Finder plug-in that allows svn commands via the contextual menu in the Finder - and badges the files icons depending on their status:

Very cool.