Sniping has nowaday become a popular form of picture taking. Sniping is when you take other people’s picture discreetly. FYI, sniping is usually done on those handphone with cameras. So be warned that there are thousand of snipers out there, armed with Camphone (megapixel or VGA) trying to take pictures of anything. As per norm the preferences for subject matter is girls.
There’s also another technique which I’d like to call Daylight Murder as it involved you taking pictures openly. This for me is the best way, and perhaps much much more polite to the people around you. And you have no qualms about being caught. As you are already doing it in the open. Thus far I have had no legal problems with this technique. And it has worked wonders for me.