Matt - All you need to do is install the windows version of Subversion, then set your PATH in cygwin to point to that location. So if it is installed in c:/programs/svn, add this to your path
PATH=$PATH:/cygdrive/c/programs/svn/bin
Author of <a href="http://www.amazon.com/exec/obidos/ASIN/1932394362/ref=jranch-20" target="_blank" rel="nofollow">Subversion in Action</a>