In John Varley's upcoming scifi novel Rolling Thunder, everyone has a brain implant that lets them google information constantly. And many futurists are saying this technology will become a reality long before we colonize Mars. The question isn't whether we'll have google brain implants (or the futuristic search engine equivalent), but how we'll handle them. What exactly would be the plusses and minuses of being able to google information instantaneously in your head, without anybody knowing you're doing it?
A google brain implant could work in lots of ways. With technology we have right now, people could wear a brain-computer interface helmet like the one sold by Emotiv, and use that to control the cursor on a wearable computer with a tiny monitor that's attached to your classes. So the thing wouldn't be implanted in your brain, but it would be responding to electrical signals from your brain. More sophisticated wearables like those described in Vernor Vinge's novel Rainbows End might allow you to google via subtle movements of your body, and then display results in special contact lenses.