It's interesting that I see Microsoft shills pop up on Slashdot and elsewhere, from time to time 'complaining' about how Linux problems with hardware changes are a majour roadblock to owning the desktop
... yet, when in real life, it's almost always Windows which I see having problems with hardware changes, while I've experienced Linux shrugging off a complete motherboard upgrade (P2 -> P3) a decade ago, and getting better ever since.
In fact, I use a hard drive that I pulled from a dying laptop as my 'traveling Linux box'. Any machine (desktop or laptop) which can boot from a USB drive is a happy host for Linux with no, or little, change to the system (sometimes resetting the X display for odd video cards). The biggest 'problem' is that, under Ubuntu, every ethernet/wifi card gets a unique number.... Right now I'm up around eth10 for the newest box.
(there are relatively simple ways to fix the ethN numbering oddity, but I'm just too lazy to write the scripts).