What could be causing one circuit out, no breakers thrown, and other lights to flicker?
OK, at first I thought bad back-stab connection at a receptacle, but since this is affecting several places in the house with obviously several varied circuits I would all but guaranty you have a bad line in to your service. This could be anywhere from the connections at the utility pole, to the connections at the top of your house, to inside the meter pan, to the connections to the main breaker in your panel. 

Typically this is NOT something for a DIY to troubleshoot. PLEASE call in a qualified electrician to check it out. You may want to contact your utility first, they may send someone out for free to check their side of things.