I was speaking to somebody at the meeting last night (I'm sorry, I've forgotten your name...), who asked me about lists of Linux-compatible hardware. I referred them to http://linux.com/hardware, but there's lots of other good ones, depending on what you're looking for.
http://www.linux-usb.org has a great list of working devices, and lots of other USB resources. For printers, http://www.linuxprinting.org does much the same job, with compatible printers, HOWTOs, and links to the drivers for Ghostscript, GIMP, etc. The SANE web-site (http://www.mostang.com/sane/) lists supported scanners. For soundcards, the kernel-supported cards are listed at http://www.linux.org.uk/OSS/, or look at ALSA (http://www.alsa-project.org).
This is the sort of stuff that we need a SLUG FAQ page for. This isn't an exhaustive list, I'm sure somebody else has something else to add. But I think it covers what I was asked last night.
Cheers,
Peter, who longs for the day when buying a Linux peripheral
doesn't have to involve a week of disappointing research.
