The <object> tag doesn't work? vshare uses <object> tag for embedding videos. I don't have phpbb anything so wouldn't know but I do know that vshare has <object> available for embedding videos...but since I might want to post a video in a phpbb forum somewhere...I think I'll check into the FAQ for a phpbb forum about how to embed a video into a post, like they have for "how to put an image" or "how to put a sig".

UPDATE:
Aparantly being able to embed youtube videos in phpbb boards is a mod that needs to be installed into the phpbb. I would imagine that a similar mod would be needed to be done to phpbb for vshare?