According to the folks at Dialidol.com:
Syesha Mercado seemed to be the tops in terms of call volume. She was followed by David Cook.
According to the site, the bottom three this week are (in order) David Archuleta, Jason Castro and Brooke White.
The website correctly predicted Carly Smithson's exit last week. So, if White goes home, they'll be correct two weeks running.