Just to drag this in yet another direction, there are mics with USB outputs and I've seen an adapter that you plug into a regular mic's XLR connector that outputs USB. But like has been said, you'll probably need a driver and you probably can't hook up more than one without problems unless the drive is written for multiple devices. From what I've seen, those mics are aimed at the Podcast market, not filed recordists. With those mics or the adapter/mic combo, the mic ends up providing it's own phantom power, has its own preamp and does its own A/D conversion (at least I think so). In fact there is a mic that IS a recorder but its not something we'd normally use.
For what its worth, I'd bet that many of the current digital recorders are running a dedicated and stripped down version of Linux.