How close is twitter to an old school mailing list? So take a list server like majordomo and create yourself a list. Allow people to subscribe t0 it – that’s follow sorted, allow people to see who else is on the list – so that’s seeing your followers. emailing it yourself is updating your status, anyone else on the list posting is @you. Direct Messages would need to be dealt with by mailing the list owner (i.e. you). You can delete users from the list – block?
If anyone is allowed to create a mailing list on the server, with an admin being allowed to delete lists, then you have a basic twitter clone. Then you need a slim client for your desktop/phone which only pulls down email messages which have come to you from the list server – so that’s your public feed. A decent search system should deal with #tags.
Oh and restrict messages to 140 characters!
Facebook is much the same, but Instant Messaging needs something a bit clever to ensure real time interaction. So enhance an email with an additional tag “IM” and enhance email servers to contain an IM service which picks up these messages straight away…
Throw in an SMS gateway and a integrate your Voicemail and you have all your messages in one inbox, just handled by different or more flexible clients.
That just leaves SPAM as the issue – Twitter has this sussed, as it’s just a server based whitelist. So providing your contacts are held on your mail server, then this works for email too. The real big issue with e-mail is the fact than e-mail servers are just that – you really need the groupware approach a la Exchange/Gmail etc so that contacts can be used to filter email at the server, and the clients sync both email and contacts (and calanders) with the server.
Hmm – should knock up a prototype really shouldn’t I!