AUSTIN, Texas - Here at the Interactive/Film week of South by Southwest, the question arises:

Is it possible to own too many pairs of shoes?

The title characters of Sneakerheadz, David T. Friendly and Mick Partridge's lively, pop-cult-savvy documentary about sneaker collectors, would agree with Imelda Marcos that it is not.

With appearances by sneaker obsessives including rapper Wale, comedian Mike Epps, and DJs Samantha Ronson and Clark Kent, Sneakerheadz perceptively tells the history of athletic shoes, from Chuck Taylors to Air Jordans, digging into issues of hip-hop fashion and cultural identity. It shows how the Internet - and shoe manufacturers' focus on limited-edition models - has changed the collecting and the resale market, making it an often lucrative and sometimes tragically dangerous game.

Philly connection: One of the featured collectors and major players in the Sneakerheadz story is Japanese shoe-hound Hommyo Hidefumi. He fed his obsession while attending Temple University in North Philly, and he built a sneaker-store empire back in Japan, starting with shoes bought at the 215 boutique and resold at enormous markups in his native country.

In Austin on Monday night, I rode my rented bike over to a screening of Swedish director Fredrik Gertten's Bikes vs Cars. Bike is by far the best way to get around SXSW, with Austin streets often gridlocked if not shut down, and a noticeably higher law enforcement presence than in previous years. That's due to the four drunken-driver-caused deaths (one of whom was on a bike) at SXSW last year.

Bikes vs Cars takes a hard look at the worldwide conflict between drivers and riders - with clear sympathy for the environmentally friendly pedal pushers. Gertten focuses on bikers fighting for their rights in car-choked São Paulo, Brazil, and in Los Angeles (interestingly, the only U.S. city featured). In Toronto, Mayor Rob Ford, elected with a pro-car suburban mandate, erases existing bike lanes and shows contempt for bikes. In Copenhagen, an amusingly put-upon taxi driver finds the swarms of riders an impediment to getting his job done.

Gertten serves up scary numbers about the continued global growth of the automobile industry. There were 1 billion cars on the panel in 2012, and will be 2 billion by 2020, the movie asserts. But his arguments in favor of people-powered (and publicly funded) transportation don't explore the effect of bike-sharing programs like the one set to debut in Philadelphia, at last, this spring.

Still, the clashes and challenges facing riders and drivers all over the world in Bikes vs Cars will be all too familiar to those who attempt to traverse Philadelphia's narrow streets on a daily basis.