But GNOME likes a hefty processor.

If you're after something secondhand, but not too old, a recent Dell Latitude should be great with Ubuntu. I have a work-supplied D620 that's about 2 years old and the only thing Ubuntu doesn't understand is the modem. And for all I know, Gutsy Gibbon can see it anyway (I haven't upgraded yet). The D620 has WiFi, Bluetooth, IR and some variants have a GSM modem in them, too. The display is 1440x900, the HDD is pretty roomy (mine's a 100Gb) and the processor supports hyperthreading.

GNOME in Ubuntu can Just Work, but you may need to do some hand-holding to migrate people to how GNOME works with files. My father took some training, but then he was upgrading from Windows 95, so he had further to go than most. If your family is coming from XP/Vista, then a lot will already make sense. Stuff like USB-connected camera picture importing is similar to how Windows does it, for instance.

Wade.