timeout error message

I have an Apache 2 web server that runs some CGI scripts. The CGI
scripts take a list of jobs and process the jobs. If the list is
pretty long than the script could take a very long time to run and can
hit the Apache time out limit. When it hits the limit I usually get
the standard apache 500 error saying there was some internal server
error. I figure I can do a couple of things...

1) increase the timeout variable... or
2) rewrite the script to constantly send some message back to the user
that it is still processing.

The first is good, and I've done that... But what happens when I hit
that limit... I'll get the same error message. The second is probably
the optimum solution, and I am going to have to do it... But what
happens to the other scripts. I have over 1000 that could potentially
have this problem. It would take an awefully long time to go through
them.

I was wondering if there was a way to display a special "timeout
error" page which says that the script is taking too long to run so
that the users know the exact problem. The internal server error would
still be needed for when the script really does fail, but the timeout
error page will be used when I hit the timeout.

If anybody can provide input, that would be great.
Thanks,
Scott