Preload Twitter user accounts using OAuth via matched usernames

UPDATE: I was able to tie together a preloaded Drupal user account with a user's OAuth login upon login without the user having to go through the registration process.

1. Add the user as a Drupal user including profile details like website URL, bio, etc., OG settings, user role, etc.
2. Manually insert the users Drupal User ID [uid], Twitter Screen name [screen_name], and Twitter User ID [twitter_uid] into the 'twitter_account' table in MySQL.
3. The user logs in to the website using OAuth and all of their profile and security information is in tact.

The issues with this are:

1. It's manual. I don't have to do it often so it works but still manual.
2. I had to user a Twitter API call to obtain the users [twitter_uid] based on their Twitter screen name. This is messy as again it was manual.
3. Did I mention it was manual?

So, does anyone have any ideas how to make it not so manual? Maybe a form to dump the Twitter screen names in and an easy button at the bottom?

Thanks!
Kevin