Just Call Me Jack

First, cd to the directory that once held the file you want to restore.  Then, run the following to get a list of all the files that were in this directory at some point, along with revision numbers:

svn log --verbose

Find the file you want to restore, note the revision number from the revision BEFORE the file was deleted.  This is what you'll be restoring.  Next, use the following command and format to being that file back from the dead:

svn up -r 20935 file.txt

Voila, you are now a SVN Voodoo priestess.  Don't forget to commit the file back into your local repository.