I've never heard of them being used for an upgrade before. More likely you'll be laughed at. People pull a lot of stunts to try and get an upgrade and an ASIC is probably a pretty lame one.
However, I've used mine (that said, it's got a big QANTAS across the bottom) to get exit rows on both Jetstar and Virgin when I've been forced to fly them. A police badge would probably work just as well too.
