froogle way to network without router

This might be old-hat for many of you; but I thought I'd share. Are you aware you can network your iMac via the airport to other devices with wireless cards without using a router? My wife shares my iMac dialup service with her Dell laptop; this would work even better if we had broadband. I share her printer. We transfer files at will. The catch is I have to be on and so does she; but that's not usually a problem. It only takes a minute to turn on the airport and set up sharing of internet in preferences. She connects just like she would to any wireless network. I'm not saying this is a substitute for a router, but it is almost as good for no extra money.