I recently set up an HP all-in-one printer/scanner/fax (an Officejet 5610) on my house network.
Thanks, HP, for providing free drivers for the printer and the scanner. I set up the device directly through my OS and I don't have to use a crappy vendor-specific frontend to scan and print. I've had a bad experience with a Brother scanner (which didn't provide an open source driver, only a really flaky binary), so this is quite refreshing.
In Ubuntu, the printer drivers (PPDs) are in the package hpijs-ppds and the scanner drivers (SANE backends) are in the package hplip, I think. Our Officejet now happily scans and prints over the network with SANE and CUPS. Standards, I love you.
Which reminds me, I'm also thanking my lucky stars for the free drivers for components on my Thinkpad X61s. The Intel integrated graphics (965GM) and the Intel wireless chipset (4965AGN) just work out of the box on Ubuntu. Thanks, Intel!