I watched three former world #1 players on the courts at Saddlebrook this morning: Jim Courier, Martina Hingis, and Justine Henin-Hardenne. Courier is retired but competes some on the senior tour, Hingis is kinda retired but certainly looked like she was gearing up to play again (and she's hardly over the hill!), and Henin-Hardenne is coming back from injury. There were a few other pros (Mardy Fish, Chanda Rubin) training as well, in addition to some very impressive junior players. It was fun just watching them hit in drill sessions and practice sets.