OS X Tiger can validate fonts!

Who knew? It's built in.

Apple - Pro - Tips - Checking for Bad Fonts:

Anyway, finding out which fonts on your system might be corrupt was no easy task, but in Tiger, it just got a whole lot easier. Here’s how to search for rampant font corruption: Go to your Applications folder and launch Font Book. You can either click directly on any font that you might think is suspect (look to see if the font is sweating), or Command-click on the fonts you want interrogated, then go under Font Book’s File menu and choose Validate Fonts. This brings up a Font Validation window and if your fonts are on the up and up, you’ll get a little round checkbox beside them. If there’s reason to believe something may be wrong, you’ll get a yellow warning icon beside a font. If it’s corrupt, you’ll get a round icon with an X in it, telling you not to use this font. Click the checkbox beside that font, then click the Remove Checked button to remove this font from your system.