I want a wireless card that will work right out of the box. I also want to be able to use encryption. Ideally, the card would be a PCI card, although if there is some really easy to use USB card, I might use that.

I will probably install Fedora to use this, although I would consider Debian or Ubuntu. Please note that I am not a Linux genius and that I don't have the free time and ambition that's needed to become one.

You don't have to become a "Linux genius", but if you're not prepared to spend some time and ambition, don't even bother ... Stick with Windows ... Bill and Steve will do whatever they can to avoid making you think. Heck! They'd like to pass a law forbidding you to think.

http://linux-wless.passys.nl/

I use a Safecom SWMULZ-5400 USB adapter which has very good support in Linux. It uses the zd1211rw driver which is built into the kernel these days. In Ubuntu you can simply plug the adapter into a USB port and it's installed, the network manager applet will immediately show you any available networks. In Debian you first need to obtain the firmware and install it in /lib/firmware/zd1211 (the firmware in the Debian repos is compiled for an older proprietary driver and won't work, so obtain the correct firmware from sourceforge). There are lots of other well supported devices. A great place to find out which cards/USB devices are supported is http://linuxwireless.org/ and specifically the supported devices page

If you pick a well supported adapter it's much easier (effortless in fact) than in other operating systems, being genuinely plug and play as opposed to plug, detect new hardware, install driver, bombard user with pop ups announcing new hardware found, new hardware recognised, new hardware now ready, etc etc.

well said.

A small and rather cheap USB-connected wireless card from A-Link, named WL54USB or something (check their site - there's only one you can find there on the front page, and that's it) works if you don't mind it being USB connected rather than internal. The package even says it's supported operating systems are blah blah blah and Linux and no lie. A couple of distributions where I've plucked it in were on air instantly (well, after I typed my WPA passphrase, of course) - kernel module used is zd1211rw, which should be there in just about any distribution you pick up. Or so it seems to me. And it's price? Less than 20€ with taxes (see a-link.com for prices near you), not much especially if you take into account that it's small, you can easily switch it from a machine to another and it indeed does work on Linux (and of course the Other OS).

And I don't wonder if you get it for less money somewhere if you care to look at. Shortly put it's a great device, a lot less headache than I expected, cheap and small.

EDIT: this seems to use the very same chipset -- or at least eats with the same driver -- than the other one mentioned above. Go for it!

The trick is finding a card with a linux supported chipset. Artheros and prism are well supported.

Ralink supplies linux drivers and most distros include them in their kernels. Unfortunately, ralink linux drivers are not the best and wpa may not work and does not work on rt2500.

I have a Dlink air plus extreme G pci card. Dwl-G520, H/W ver. B3, F/W ver. 4.10. This card works well and out-of-the-box. It should support wpa too but this I have not tested.

Concerning the rt2500 chipset: it works well with the serialmokey cvs driver. Wep and wpa encryptions are not any obstacle.
BR,
Cappa

Atheros Communications, Inc. AR5212 802.11abg NIC

Another vote for Atheros! I don't think there's anything you'd likely want to do with a wireless card that this one can't do. There's in-kernel support for it now, but I'm not having much luck with it (maybe I'm doing it wrong?). I'd recommend the madwifi.org drivers until ath5k is a bit more mature.

See http://linux-wless.passys.nl for a long list of what works, what doesn't, and what people recommend.

Oh, and pay attention to the version number. Gizmo rev. A may work while Gizmo rev.B doesn't - stupid manufacturers keep the same product name and model but change the chipset.