I have this computer with ubuntu with a wifi PCMCIA card that I'm taking care for someone.
The range sucks on that thing. It's far enough that getting an IP with DHCP takes around 30 seconds. It's not bad, but I am being asked to reduce the time so the auth and DHCP is done transparently on the spot.

It's none of linux's fault. The range sucks on Windows or Linux. Under Windows ME, it would crash when comming out of hibernation (latest driver and client). Under linux, it needed a driver upgrade for stability and script tweaking for convinience with initng. Of course, Windows and Linux competes in my environment, and linux can't help but keeping getting blamed since it's new.
I keep insisting it's the distance, the cheap hardware, but not linux's fault....

It's a madwifi card.

I ran athctrl -i wifi0 -d 50 in a wild attempt to make the connection more stable.

Is there anything I can do until I implement mesh networking on my network?

Latest madwifi drivers should be better for you. You can also do some static IP config. Maybe increase the transmit power, but i don't know how to do that.

I have the latest (relatively, they update each week or so no?)

Transmit power would be iwconfig ath0 txpower 17db or something like that (man iwconfig). Madwifi has been known not to work too good with transmit power, but it's worth a try.

nice nickname by the way.

Does the computer roam between APs? If not, then you could try Disabling Background Scanning in Client Mode. I am not sure whether this will really help much though.

This will remove the 2 second scan each 2 minutes, but doesn't make the link any stronger, or increase sensitivity theoretically.

By the iwconfig output, it says that the current txpower is 15dBm. I could try cranking it up to 17 and/or 18, but it's a weak card, it might not go any higher.

So far:
dBm adujustment
sensitivity adjusment
disable background scanning
static IP.

I'll check those out. Thanks.

if getting a stronger card is an option, perhaps look into a seano card (just cross check that the card will work under linux) as they have some VERY hot cards (200-400 mw instead of the normal 50ish tops)

I'll check that out! thanks.