I even once threw a sound card into a Linux box, turned it on, let it sit there a month before I got around to downloading and installing the sound card driver, and the funny thing is that I build the kernel module, loaded the module and had sound without having to reboot the machine. That is cool.
That's nothing. I tossed an ISA NIC in a box that was running, because I didn't feel like shutting it down. Loaded the kernel module with parameters matching what I had it jumpered to, and I was on the network in a few seconds. :)

(Note to kids out there: Don't try this at home, or with PCI cards.)