Install Subversion on Mac OS X Lion (10.7)

Edit the SystemVersion.plist file to change your Mac OS X version from 10.7 to 10.6:
sudo vi /System/Library/CoreServices/SystemVersion.plist
Replace each occurrence of 10.7 with 10.6
Save the file
Install Universal Subversion 1.6.17 Binaries for Snow Leopard (Mac OS X 10.6) from http://www.collab.net/downloads/community/
Revert the file we edited previously (10.6 to 10.7 this time)