The following command will find all svn folders from within your current working directory and delete them all. In short this will make working directory as exported project.
find . -name .svn -exec rm -rf {} \;
Explanation:
The find command will start searching from '.'(Current directory)
Will find the file/folder whose name is '.svn'
The -exec will execute 'rm -rf' command on the result of find command. i.e. the {} will return all files/folders returned by find command.
And the last '\' is important it is escape character.
So you are done....
Be aware you are using rm -rf command..
(I have tested it on Ubuntu 6.06)