Is there a better way to show UID in comment loop?

Here’s what I’m using right now:

‘ (UID#<?php $user = get_userdata($comment->user_id); echo $user->ID; ‘?>)

but that code is slowing my site down a bit. is there a smarter way to show the user ids in the comments?

here’s an example of what I’m doing:
http://www.myconfinedspace.com/2009/08/29/fetching-smile/