If you aren't a professional how do you normally get your camera into the show? I know most venues say no SLRs but do they actually enforce that? I have been told there isn't anyway into the photo pit without credentials but just want to run that buy some people who may have actually shot at shows before.
tl;dr
How can I get my camera in without credentials and is it possible to get into the press pit?
The short answer is... you are out of luck. Unless you have a newspaper, magazine (or some high end contact back stage helping you), and have made and been approved via application months in advance, there is zero chance to get into the photo pit area without a press pass.
There is some little good news with this, though... in the photo pit, you are shooting upward a lot and the angles are FAR from optimal, resulting in distorted looking pics. You are closer, though.
Now, this is not always the case. As you have seen, there are many music festivals that are not in true concert venues (auditoriums and/or closed in and controlled areas). This was my good fortune recently, and I just walked in with a backpack full of camera equipment without so much as a 2nd look.
However, for most "traditional" concerts, they will let in the P&S cameras and cell phone cameras and what not, because they KNOW the chances of getting a good shot are slim to none, and not permit the kinds of cameras that can get the shot. They will always tell you that flashes are NOT permitted. That is because a high-end flash can really temporarily blind a performer causing issues with his performance. No one wants that (I had my Nikon SB-800 with me... but I would never dream of using it at the concert!).
I suppose the workaround to this is to find a higher end P&S camera. I have the now discontinued Nikon E8800 and it has given me some impressive night shots (it has built-in VR, ISO up to 400 and a 80X zoom, shutter speeds from 30 seconds to 1/4000th and shoots RAW format, all in a small palm-sized camera, and there are also cameras like the Canon G9 who could come closer... but still not near the quality of a dSLR with a big lens.
Bottom line... if they say no dSLRs and are watching for them, even if you manage to somehow sneak one in, if they spot you, they may escort you out of the premises, camera and all.