Morse Academy, which is available at
http://www.speroni.com/AH0A.html has the ability to send visually. It sometimes takes a little bit of tinkering to get it to work in Windows XP, but in some respects, I like it a little better than G4FON. The option to change to visual signaling is under Options/Tone Generator if you're able to get the program working. I've also heard of programs that will flash an LED on the keyboard, but I cant think of the name of the software now.