Leo Laporte, The Tech Guy, recently recommended Vidblaster, Wirecast and BoinxTV for creating a webcast with professional looking graphics. These software products all run about $500. Leo uses TriCaster, a hardware solution, that costs $12,000+.
Vidblaster runs on Windows only and comes in 3 versions: Home, Pro, and Studio.
Wirecast runs on both Windows and Mac.
BoinxTV runs on Mac only.
