1. Lesson Plan
2. Prepare before going into the classroom
Seriously, if you are planning your lecture while doing it, you're doing a huge disservice to your students. That's not to say that open discourse and exploratory learning aren't good in the classroom, this can be great - let the discussion go where the students take it. But on the technology/course material side, I would be very concerned with adding material to my class at the last minute. What happens if that image/movie/website that you were counting on weren't there? What if your connectivity tanks when you wanted it? What if you get that huge phallus instead of the ICBM that you were looking for? I download anything that I want to use ahead of time.
If you are doing this last minute, to me that demonstrates that you are not taking your planning/prep seriously (or that you are lazy), and that you are putting your laziness ahead of the learning of your students. They (the students) deserve better than that.
Now that I've nibbled at the troll-bait, I think this is seriously off course - search by sketch, search by term, they all have the same possibilities to return content that someone out there may find offensive. So I fail to see how this is any different. That's the glory & risk of the Internet - use at your own risk.
...This really only sounds useful in more rural areas.
Your post, Sir, assumes that we people in rural areas actually obey traffic signals. Especially during non-peak hours (I've never observed vehicles blowing red lights @ 3 a.m. down my street).
Live within your income, even if you have to borrow to do so. -- Josh Billings