See the Programmer's Cards:

 Press [S] to have the batter spit. Keep pressing it until the
 programmer baseball cards appear.

 Secret Teams:

 Click on "Help" and then on "About Baseball 2000". Now, on the first
 occurance of Wizbang, right click the mouse twice. It's on the 2nd
 line of the Copyright Declaration. Do that and you will be awarded
 a Special Team.

 Special Teams:

 Microsoft : Play with the Microsoft Team (how suprising)
 Robots    : He
 Wizbang   : Developers in Ball Uniforms (including women)