TweetingSince: Twitter users who registered the same day that you did
TweetingSince is a simple service that tells you who are users who registered on Twitter the same day as you did.
Just tell your username, click Go and in a couple of seconds gives you a list of users who registered the same day. The list shows the 100 most influential users and includes the name, bio, number of followers, number of tweets and the locality.
This tool is part of a service offered by HubSpot called TwitterGrader that tells you how you are influential on Twitter.