It would be relatively easy to build a Twitter service on top of email. Participating email providers would give every email account its own listserv account. F

It would be relatively easy to build a Twitter service on top of email. Participating email providers would give every email account its own listserv account. Followers would be subscribed to the list. Tweet emails would have only a 144-character subject, no body (plus any multimedia attachments). You could still use your email normally, but also access the full Twitter functionality with a special client via the web, phone, or computer. Anyone with a normal email account could follow you, though they would have to have an account with a participating email provider in order to tweet or retweet. If a couple of the big players implemented it, the service would have critical mass overnight.