Combining old and new:

Wrigley Field
Veterans Stadium
Three Rivers Stadium
current Busch Stadium
previous Busch Stadium
Fulton County Stadium
Riverfront Stadium
Astrodome
Jack Murphy Stadium
Mile High Stadium
Cleveland Municipal Stadium
Jacobs Field
Tiger Stadium
Comerica Park
County Stadium
Miller Park
Tropicana Dome
Comiskey Park (pre-1991)
Comiskey Park/US Cellular Field (1991-cuurent)
Kaufmann Stadium
Metrodome
Oakland Coliseum
Arlington Stadium

Plus, of all these that I have officially ballhawked in (remove Metrodome and Arlington Stadium), the only one I haven't secured at least one baseball in (BP or game) is the current Busch Stadium, and I've only been there once.

Dave Miedema