Evan Williams, co-founder of Twitter, is up next.

Twitter – simple app, framed around question of ‘what are you doing’? 140 character messages, via phone, web, and an ecosystem of apps.

Aggressive application of constraints could have benefits for apps, developers, and users.

Not anti-feature, but “what can we take away to make something new?”

Twitter, for example, is essentially a blogging app. But limited to 140 characters, and doesn’t have titles, categories, etc.

Twitter UI has “very low cognitive load” (ie it’s simple).

Twitter api also simple, leading to an explosion in third party apps.

Where else can you take things away to build something new? Fotolog, with one photo per day posting limit? YouTube 10 minute/10Mb video upload limit? A social network, limited to ten friends? A dating site without profile information other than a photograph? Email with a 20 message cap on the size of your inbox? A MySpace competitor, restricted to just college students? A competitor to Yahoo, with a minimalist white page and a single search box? Hmm, maybe that one’s been done, eh?

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