I simply went in with them (I sneaked in with both - in a baggy bag - one Canon 400D and one Konica Minolta DiMage Z6 - none are small). I had made friends with the lady at the entrance desk and she offered to ask the guard if I'm allowed with cameras in. Apparently, cameras weren't allowed, and she said that the security people had told her that there would be a check point. However, when they opened the doors, no checking, they simply checked the tickets and just let everyone pass without further questioning. And God knows my bags looked really heavy
I still kept my cameras concealed, fearing the huge bodyguards in front of the stage, but during the show I took photos all the time, both cameras slung around my neck, shamelessly getting up and applauding, both cameras very visible. The bodyguards had no problem with people taking photos at all, however. They only reacted to those folks, who weren't authorized photographers, that got too close to the stage. I did not use any flash. More out of respect for people's eyes, than out of fear of being caught or anything
i bet it works. Also, try to take 2 cards, or 2 batteries with you. in case they tell you to leave your camera, tell them it's very expensive, no you're not leaving it, but you're offering to leave them the battery or the card, or even both 
(if you can get doubles for both of them actually 
maybe 80% in Hungary and Poland. and even less in Denmark.
