Yes, they do - in the right hands (Score 2, Interesting)

I've been using PC-Lint since about 1997, and have found some pretty nasty bugs using it - in most cases well before they had surfaced in the field. Given that, using such tools is (for me at least) a no-brainer. You do however need to a a particular mindset and take the time to learn how to use such tools effectively - how to tune your warning policy to your codebase, and what issues to look out for which could indicate real trouble (e.g. I've seen behavoural bugs caused by variable name scoping issues which lint caught but which at first glance would appear to be "lint noise"). I have a red flag list of issues I watch for in a new codebase, which works rather well in practice. I should add a disclaimer that these days I make most of my living from working with PC-Lint, so I'll acknowledge my interest in the subject up-front before anyone else points it out!