How one goes about impressing students these days, God knows. Live satellite pictures are accessible to anybody with a PC and a modem. Up-to-date ones - those showing Iraqi military movements, say - are rare, admittedly, but not for technical reasons; it's just that the US government won't flash them around. Satellite images are expensive and people aren't likely to give them out.
One exception is weather satellite information. This is probably, like so much of the stuff around on the Internet, because nobody could come up with a reason why it shouldn't be there. However, you still need a meteorology degree to get anything out of it. Real weather satellite pictures don't look like those Technicolor things that Suzanne Charlton shows after the News.
One of the things about the Internet that really scares the authorities is that the economics of information access is shifting. Material that was once only available to people with millions to spend is now common currency.
As the Internet allows people to access information from disparate sources, they are able to deduce far more than perhaps they should. India's nuclear scientists were able to hide their activity from US spy satellites by pulling information off various websites and working out when spy satellites were likely to be overhead. They simply stopped work at the relevant times and fooled the CIA into thinking that nothing was going on.
Satellite images are one of the more high-profile examples of this, but allowing the public access to expensive information can cut both ways. Artificial intelligence departments can place their latest "chatterbots" on the Internet and allow them to talk to a huge range of people, enabling researchers to work out how well they respond in a far shorter time.
Where all this will end is difficult to say. As information becomes more widely available, privileged data increasingly becomes an anachronism. Stealth bombers were reputedly invented in the 1940s and conspiracy theorists claim that the US military is about 40 years ahead of the game. That is probably propaganda. It is increasingly clear that if the Americans really did have computers working out their strategy, people would likely have found ways of talking to them over the Internet a long time ago.
Weather satellite pictures
An excellent place to find "chatterbots" - computers that you can converse with