I agree with Scott that Apple is just plain wrong in making its users launch Safari and Mail in order to change their default to something else. I understand why they do it - I just don't agree with their tactics. That being said, there are ways to avoid doing it Apple's OS X way and instead do it the old Classic Internet Config way. Launching Safari is no big deal, obviously, but you shouldn't have to if you're not interested in using it. Having to launch Mail in order to tell it that you want to use something else is a bit more of a pain since you can't launch Mail and access the preferences without setting up an account! Why must I set up an account (even a bogus one) in a mail client that I don't plan to use? Fortunately most mail clients ask you when you launch them if you want them to become your default. That's a good thing. But some of those apps (Entourage comes to mind) only ask you once and if you decline at that time you're back to square one.
MisFox, More Internet and RCDefaultApp are the three apps that come to mind for Scott (and anyone else who cares) to check out.
- MisFox stands for Missing Internet Settings for X and it's a GUI app for changing a variety of internet protocol settings. MIME type settings and helper apps.
- More Internet is a system preference pane which does pretty much the same thing, and it's Universal Binary.
RCDefaultApp is also a preference pane and does all of the above and then some. It, too, is Universal Binary.
All three will handle mail client and browser default settings without having to ever launch Safari or Mail if you don't want to. All three are free. A colleague just pointed me to IC-Switch, which I wasn't aware of previously and it does all those same things in regard to Internet Config settings - but it installs as a menubar item so that you can change defaults on the fly.
If you're aware of other apps that do the same thing, let us know in the comments!