mrogish, you are absolutely correct. If the user just has one long sentence, it would circumvent the hack. Well, the original one. The change I made eliminates the entire signature.
I was fudging around and decided to try making a character limit, a total lines limit, as well as an image size limit for sigs, controllable from the Control Panel. I guess something would have to be added to make it look for <br>'s as well - might as well make it totally functional.
For some reason, I get more excited about tiny little hacks like this than I do for huge PM and Poll hacks and such

.
-jim