This updater allows you to easily update wiremod, phx, spacebuild, gcombat, and many other svn based addons through the use of a single frontend. I did not make this program, but I’ve found it so useful that I took it on myself to make a thread about it.
You can download the updater from: : http://www.tezzanator.net/download/click.php?id=1 .
Then extract these files to where you put the updater: http://www.garrysmod.org/downloads/?a=view&id=39988 .
Just click on Gmod Auto Updater.exe to get to the frontend where you can select the addons you want to install. All you need to do is tell it where your addons folder is, and bam in a few minutes you’ll have all the svn mods you could want all from one simple program.