The OpenDNS blog has an excellent write-up on some really um...sorta evil practices that Google and Dell have teamed up to deliver to their customers. In essence, it's spyware. Error URL's are really common with inexperienced users. The redirect leads you to a page full of ads. No help. No suggested correction. Nothing. It's slimy. A huge percentage of computer users have no idea they're looking at advertisements. In fact, Google's ads don't look like advertisements at all. It's just text on a page. No fancy animations or colors. Just a bunch of text that pretty much looks like search results.
Even worse, this tool is buried away in some non-descript application that you have to manually uninstall. As Google continues to grow, they're finding that it's going to have to pay for those precious default settings. Huge numbers of people never change things when they first plug in that PC. So Google has partnered with hardware makers to install toolbars and the like. That's fine and good. But there is a line where you're effectively misleading novice users with ads that look like bona fide search results.