It seems that all of the initial Google results for \"using subversion with xcode\" are actually just tutorials for installing and configuring svn and Xcode, as opposed to a
A lot of people have problems using the build in svn client, especially to get a new project into svn and that it works.
I created a straight foreward tutorial on how to do this, along with a very well known pitfall (works for Xcode up till the latest version of xcode incl. Iphone 4 sdk)
http://www.sodeso.nl/?p=599