Have not been, but I was following and in 2011 Warner was giving out these poker chips each day, so it took me a while but I broke down and got them.
Also at Warner they had these lanyards. The one on the right was available at NYCC as well as other shows in 2010 but they didn't give any out in 2011 or 2012 at NYCC only at SDCC so I got those too