Have you thought of submitting your mods to phpbb.com? I was looking for exactly this mod, but couldn't find it. So I wrote it myself and just submitted it to phpbb. They have released it here:
http://www.phpbb.com/phpBB/viewtopic.ph ... 33&start=0
Then I found yours afterwards
Mine is a little different, and I changed the style so that the names are not underlined.
