I just sold one of my Minis (a CoreDuo 1.83 GHz Late 2006) to Elfen, and I intend to eventually get a 2009 Mini or something (just to have, since they're so handy). Maybe a G4 as well, mostly because, as this thread has pointed out, they're getting cheap enough, and they're old and slow and common enough, that people practically can't give them away (it seems).

And, if anybody ever gets OS 9 running natively on one, I'd be super happy (they take up so much less space than a G4 tower).

c