The difference between a stranger sending you a message that you might be interested in at a very low volume level, no repetition, just sending it to very few people, and that being done as spam - those things get close enough that you want to be careful never to filter out something that's legitimate.

It's pretty incredible to look back 30 years to when Microsoft was starting and realize how work has been transformed. We're finally getting close to what I call the digital workstyle.

In the old generation, if one kid bought a PlayStation 2 and the other kid bought an Xbox, at his house you played PlayStation, at your house you played Xbox. Now that it's online, all those early buyers who... you want to play with, they've got their reputation online of who they are and how good they are at these games.

Don't let yourself be lulled into inaction.

As you get to the end of the project you want to run all the tests cases against one version and make sure that you know that that version passed everything. And so as you get late in the project you get a little more conservative about making radical changes to the software.

I believe in generous aid policies.

Bioterrorism is like earthquakes, you should think in order of magnitudes. If you can kill 10 people that's a one, 100 people that's a two... Bioterrorism is the thing that can give you not just sixes, but sevens, eights and nines.