I was pretty well camped in this school of thought as well, but I was going through use cases in my head and it kept nagging me that the iPhone has a ".com" button on the keyboard by default when you're entering a URL. So I made this post...

The advice has been strongly for a .com, and there have been a lot of really good reasons as to why. (In other words, my opinion has been successfully swayed.)

I think axod made a particularly good point with mibbit; 6 months ago I wouldn't have ever connected the words IRC or chat with the word "mibbit", but I do now; and I don't think I've ever forgotten the domain name.

I suppose any more people don't correlate the domain name with what it does as much as they used to.