All questions at tech conferences come from one of two sources:
1) Yehuda Katz.
2) Yehuda Katz.
The best thing to do with questions at a tech conference is to ignore them completely. The second best thing is to turn them into advertising for yourself, your company, your favorite language or open source project, or, if there are attractive women in the audience - rare but it happens - your sexual prowess.
However, you may, in your foolishness, decide to take questions seriously, think about them, and see if you can learn something. Maybe Zorak have mercy on your soul. (Zorak is the parking god, who prepares spaces to park. All glory be to Zorak.)
God I forgot what I was going to say.
Oh yeah. The real way to take questions in a tech talk. Don't be like ok are there any questions. People will be like, oh shit, I had something I wanted to say, but I forgot what it was. Other people will be like, I've got the only good question in the room, but I'm shy and kind of weird in the head, so I'm going to cautiously half-raise my hand and then drop it and hide it the minute I think you might actually call on me. Still other people will be like oh look at me my question is stupid but I can talk for a really long time before anybody figures out how stupid it is because I know lots of obscure terms even though I don't know how to arrange them into an intelligent sentence.
Skip all that. Instead, open the talk with your Twitter username, and be like, at the end I'll take a look at Twitter for questions. That way you can screen out all the stupid questions. You can also screen out the questions you disagree with or which you find personally annoying. But it's better to answer a few of those, otherwise people will stand up and yell them at you anyway.
The real win is that it allows people to ask the question when they think of it, and since they're right there in the room, if they ask a question which is interesting but not totally coherent, you can ask them to elaborate. It makes life easier for shy people, and it also allows you to focus on the best questions, since you see the question before you choose the person who speaks, rather than vice versa. It's great for the backchannel, because people can discuss what question to ask before they even ask it. The 140 characters is also good discipline for the excessive verbiage crew. No matter how good their point might be, you as the speaker have to be fair to every other person with a question too, so if you get them to use their brains for brevity and clarity instead of verbosity and vocabularity, it's like converting a supervillain to truth, justice, and the American way.