publicity stunts...it depends on how brave you are lol...I mean you could shoot everyone in the crowd with an automatic weapon and that would be pretty outrageous...
In all seriousness... just think of things that would ruffle people's feathers...next time Benny Hinn makes it to Vancouver, guess who's going to try to get a permit to do an outdoor show close to the "Miracle Crusade" ...it will be complete with reverse healings (people going onto stage just fine, leaving in wheelchairs, and crutches), mock hymns, a sermon preaching against religion (done in that OOOOOLLLD time southern drawwwwl), and of course my bands music in a bit of "praise and worship" to the deity of common sence.
What's your band all about? You kind of have to think about what the band's image means before you can think about an effective publicity stunt...such as when Rage Against the Machine played outside of the NY stock exchange. Also, if you want a successful publicity stunt, you might want to be fairly open to pissing a whole lot of people off and/or getting arrested...hey, it's all in the name of music, right? =D
I dunno...what's your band all about and maybe I could see if anything comes to mind.