Putting QR code in conference poster

New piece of tech-innovation that I came across today, Putting QR codes on your poster for smartphone users.They are simple and very versatile.But among many things that one can do with QR code, one is that there are so many things that one could do with a QR code that the temptation would be strong to do all of them. The poster should not look like some mysterious stamp collection. Pick one, maybe two, things you want to do with a QR code and do them well.I tried this free link for this purpose and it gave good results.
http://zxing.appspot.com/generator/