When writing documentation, one often has need to come up with a sample URL to illustrate some point or other. When you do, make sure the sample URL is under your control.
I remember a Windows beta that used the sample URL http://www.xxxxx.com/ in a dialog box. You can imagine where that actually goes.
This web site uses www.wallyworld.com as a sample URL. Perhaps they didn't realize that it's a gay porn site.
(Raymond's strange dream story: One night I dreamt that I found a web site that had a complete Dilbert archive, and for some reason the name of the site was "Wally World". In the morning, I checked out the site and was in for a big surprise...)
So play it safe. When you need a sample URL, don't just make something up. If you do, odds are good that somebody is going to rush in and register it. Make your sample URLs point back to your company's home page, or use http://www.example.com, which the IANA has reserved for use in sample URLs. If that's too dorky, you can always go out and register the domain you want to use as your sample, so that nobody else can sneak in and steal it. (This does have the problem of incurring renewal fees.)