Hi,
Well, here's a cheap solution, that might possibly work.
Most video switchers have a chroma key effect, so, in theory:
On a computer, create a title with a solid background color. Using an S-Video out connection from your computer hook it up to your video switch, then display the title on your computer (and the S-video).
From there, you should be able to key out the background and have your title.
Now, theoretically, this would work, but I'm sure many production problems will happen, and I wouldn't really recommend it
;-)
As with compusolver, I only have basic experience with live broadcasting. (It was at my middle school.)
Also, can I ask you a question?
How do you broadcast your video throughout the whole school?