Here’s a bit of code that I always need to look up :) It finds any subversion (.svn) folders in the current directory tree and deletes them. I guess this is one benefit to using Mercurial or Git, as they only have one hidden directory at the top level. There’s no turning back from this so be sure that’s what you want to do!
As always, double-check the directory you’re in before running this command.
rm -rf `find . -type d -name .svn`