Don't use a tripod if you can help it. Having to carry one is a pain and thus cripples creativity.
Only use a tripod for still subjects either at night or when you need long shutter speeds of about 1/60 or slower.
It's a common misconception among photo teachers and amateurs that tripods are good, although no one really knows why. I guess some people just associate tripods with serious photography.
Nah, no one needs a tripod unless the shutter speed is long. Today VR and IS lenses also help obsolete them. Long shutter speeds only happen at night, or if you are at f/22 for a lot of depth of field.
Even worse, if you whip out a tripod everyone thinks you're a professional and then crowds around you as if you somehow have the only good spot from which to make a photo. I hate herd mentalities. I'm an American and proud to blaze my own trail just as my forefathers did in building our great nation. Follow your heart, not some other stranger's tripod.