If you don't want to go through the hassle of dealing with a wireless card's installation and maintenance, you'll probably be best off with a wireless adapter, which can serve the same purpose without the extra baggage. So what are your options on that front?
Linksys WUSB11: One wireless adapter that is slightly on the pricier side, but also actually works, comes from the popular router-making company Linksys. It's a 2.4GHz model, priced at around $60, and is totally USB-dependent, meaning that you won't need an extra power cord plugged into the wall in order for it to function. It's small, about the size of a wallet or so, and is therefore incredibly easy to carry in a laptop bag or even your purse so you can connect it to any computer, any time, and be connected to the Internet - always.
Belkin F5D7050: Jumping from most expensive to least expensive brings us to the Belkin F5D7050, a device that - in some ways - is my favorite and the best wireless adapter card for a Compaq laptop. Though, it's not much of a card at all, and that's part of the reason it's as popular as it is. The thing is shaped more like a flash drive, plugs in like a flash drive, but acts like a wireless card. Pretty neat, eh? And did I mention it was cheap? It clocks in at just about $15, comes with driver software, and has very few tech issues as well as a lifetime warranty. Not bad, Belkin. Not bad at all.
Compaq iPAQ 11: Last but not least is a wireless adapter that comes straight from the company that brought you your laptop: Compaq. The Compaq iPAQ 11 rocks an old-school vibe to it, but unlike the Linksys option on this list, it's only around $18-$20. I say "old-school" for a couple of reasons. Firstly, it just looks old. That 1980s dull computer color is covering the device, and while it does sport some nice blinking lights, many people report that the strength of the signal depends quite heavily on which direction the thing is pointing. Hey, at least it works, right?