Save it and exit the file. In vim speak that's <Esc> :x <CR> or Escape <shift>+; (to make a colon) then press x followed by enter (Carrage Return)
Next whack open a PHP file in vim:
sketch@talkphp$ vi phpfile.php
Next find the start of the class etc, then (whilst in insert mode) just press <ctrl>+o (lower case O not zero) and bam! there should be a generated phpDoc comment!
You will need to edit it slightly though, for example add variable types and descriptions (vim cant read your mind, yet)
NOTE: You must be in insert mode inorder for the keymap to work (as its an imap), to change this to function in normal mode, change the imap line in the .vimrc file to: