Things I'll forget
I recently aquired a new 801.11g capable router, so have had to set up dsn etc. on my boxes; for some reason this is less automatic than before with regard to the local machines, so on the router I've had to set the mapping of MAC to IP4 and nodename, and on each box I've had to manually add the others to /etc/hosts.
On the OS X and Fedora machines that was enough, as the DCHP seems to set gateway and dns without further ado; on the Solaris 9 boxes to set the dns /etc/nsswitch.conf must contain the line 'hosts: files dns', and /etc/resolv.conf 'nameserver
Sometime in the late 90's I googled (probably altavistaed actually) a problem I was having with an apache config file, and found an answer I'd written a few years before and forgotten, as it's something you only set once when you install the thing that way, so I make a habit of putting things I'll forget on the web or usenet somewhere, like this is now.