Last week, I called podcasting the poster child for occasionally connected computing. Boy, was I blind! Steve Fulling and I were at lunch today and realized the email is the elephant in the occasionally connected computing room. Back in the good old days, email was a P2P thing with MTAs (usually sendmail) sending mail to each other. Then along came the Internet explosion and millions of people who had, of all things, dial-up connections. The POP protocol became the dominant way clients got email almost overnight. POP enables occasionally connected email and email clients are engineered with occasional connectedness in mind.