The power supply finally arrived!
I have installed the new power supply and revo appears to be working properly again. I will be happy to be able to read email from bierfaristo.com again without having to use the horrible web interface.
I have been running short on space on revo for a while now, but had been holding off buying a new disk to see if I would need to replace revo. (If I had to buy a new computer, it would probably just come with twice as much space as revo has). Now that I've replaced the power supply, we should be good for another couple of years, so I think I'll buy a new disk too. There is a 160GB seagate drive on sale at CompUSA for $89 (after rebates). I'm planning to take the boys and buy the disk tomorrow.
Since I can't add any more drives (without buying a separate enclosure or something), I think I'll probably upgrade the OS at the same time. I've used RedHat linux on revo since I first set it up, but RedHat is getting out of the small-server business to focus on "the enterprise". I'll have to look at the educational pricing, but I'm inclined to jump to debian or openbsd. If I switch to openbsd, I would probably have to reformat everything, but it might be worth doing that so that I could optimally repartition the drives and start with fresh filesystems. So many possibilities!
Anyway, it's great to have the server running again.