Wow, you're a really good size! Yeah, that doesn't make any sense really, but I guess I mean big enough to show off, but not so big to be getting bothered about it. My belly is really big (and it's just one in there-- see the Oct. bellies thread) and I'm ALWAYS getting "Oh, it MUST be twins!" and "You poor thing, you'll NEVER make it to your due date!"
Some people get offended by that stuff, luckily I am not one of them!