As Eric Baković recently noted, there's been a lot of buzz about a presentation about "uptalk" by Amanda Ritchart and Amalia Arvaniti at the 2013 Acoustical Society meeting. All we have so far is a sort of press release ("Do We All Speak Like Valley Girls? Uptalk in Southern Californian English", ASA Lay Language Papers, 12/5/2013), but this is enough to see that Ritchart and Arvaniti have made a valuable contribution.
They based their analysis on systematic analysis of a good-sized recorded dataset (23 "native speakers of SoCal English", who were asked to describe a muted video clip and to participate in a "map task" interaction). They distinguished among different interactional functions ("simple statement", "question", "floor holding", "confirmation request"), they systematically noted aspects of the location and extent of rises, and they based their conclusions on a statistical analysis of the interrelationship of these features.