My wife has been asked several times about her white Kindle. Most people assume it's a smaller version of the iPad. The fact that the iPad isn't even white doesn't seem to matter. I guess Apple owns white now or something.
I've had several people ask me about my Kindle because they noticed a custom screensaver (pictures look surprisingly good on the K3's display, as long as they're not too dark and have been properly converted).
As for seeing Kindles in public, never outside of coffee shops or airports. I've seen a few people with Nooks at B&N but never any other eBook reader.