US Tennis Professionals That Have a Twitter Account

USTN sponsors a Twitter list.  You can get US Pro Twitter messages at http://twitter.com/#/list/US_Tennis/pro-tennis-players :
Currently on our List:
@MardyFish #1 American Singles Player
@andyroddick Former #1 American Singles Player
@serenajwilliams #1 American Singles Player
@bryanbros #1 American Doubles Team
@liezelhuber #1 American Doubles Player
@travisparrott Top 40 American Doubles Player
@samquerrey Top American Player
@jimcourier Former #1 American and currently on Senior Outback [...]