A View to Search by Usernames or Email in Drupal 6/7
I'll fully admit Drupal has one crappy user administration interface. And, since I get quite a few of the "can you find info about this user?" requests, which take so little time I can't bill for them :), I've expanded on the Drupal Post installation support question:
Search for username in Users list?
and created a custom view to help out my customers.
In the better late than never, I've finally gotten around to publishing it . . .