The Deleting SVN Folders meme
Perhaps I should name 5 other people to modify this script when I'm done. 
First, it was Wyatt, then Jon, then Rich - and probably many others. Well, it's my turn dammit.
I keep getting code from contractors that have _svn folders in them - and the script I got from Jon only looks for the .svn that I use.
So here is the quick fix (emphasis on quick)
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\DeleteSVN]
@="Delete SVN Folders"
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\DeleteSVN\command]
@="cmd.exe
/c \"TITLE Removing SVN Folders in %1 && COLOR 9A &&
FOR /r \"%1\" %%f IN (.svn _svn) DO RD /s /q \"%%f\" \""
My handy-dandy MS-DOS Encyclopedia came to the rescue with the syntax for the "set" part of the FOR statement.
Seems to work for me so far.. but I might be back to fix it later. Be warned 