A great article was posted on Friday over at c|net, describing how "Carl Banzhof, VP and chief technology evangelist for McAfee, outlined a scenario in which mobile phones--not laptops--could be used to sniff wireless packets". The upshot is that he took a T-Mobile MDA and made it look like a WiFi access point - i.e. showing how a malicious smartphone user could "trick" you into logging onto the internet via the MDA, thereby exposing all of your communications to packet sniffing.
I read stories like this and it makes me complain a little less about Microsoft devoting resources to security on Windows Mobile instead of "the pretty."
You still see the Internet, except all your personal data is now flowing through the criminal's machine as a man-in-the-middle intermediary.