LinuxCertified.com sells laptops preinstalled and tested with Linux. In former days, they were rebrands of generally-cheap machines (e.g. rebranded eMachines), but now they're selling a variety of unbranded machine as well as certified Lenovo laptops.
That site looks like it's from 1997. (It looks like shit.) There's no way I'd enter my CC#.
There is TuxMobil (http://tuxmobil.org/), which is trying to be a repository of installation & configuration guides for various mobile devices. It was very useful to me in the past, but it doesn't seem to be up-to-date anymore.