Can police search your text messages if you get caught for speeding?

No, I didn't get pulled over, I just found an interesting article by criminal law professor Adam Gershowitz about the frightening prospect of police searching your text messages if you get stopped for a traffic infraction. "Search incident to arrest" anyone? Wonder what my law school bloggers/techy friends would think of this one. I could find out way more on my friend's phones than what they had been texting, their browsing history, their e-mails, photos, the list goes on. I really wonder at the Fourth Amendment implications.