Airport keychain problems

Grr. Installed another software update, and yet again the wireless networking has stopped working. This has happened every time I've installed an OS update; the problem seems to be related to Keychain Access—eventually, after a few reboots I get the dialog about AirPort needing to access the system keychain, and after that everything recovers. Another data point supporting this theory: the Keychain Access program (in Applications/Utilities) sometimes hangs as well.

...

Four reboots later, the problem has mysteriously fixed itself (and without the airport system keychain dialog this time). I was just about to try some more experimental solutions, but I guess I'll save them for the next time around.

Groups

I've got a CVS repository on the Mac which is accessed by another user, and we keep having permission problems when new files are added. According to the CVS Manual, UNIX groups are the normal way to deal with this. However, Mac OS X doesn't quite deal with groups in the same way as normal UNIX boxen.

Not to worry: there are some nice scripts here, here and here to make things look more normal.

Who's That File

Because I keep forgetting: the magic incantation to figure out which Fink package owns a particular file is:
dpkg -S file