Verified answer

The problem with cameras with amazing zoom is that they get the ability to zoom so much by using a tiny sensor. Tiny sensors do not give good image quality using high ISOs. You will need high ISOs in the low light typically found in concerts.

There are a very few compact cameras that offer a slightly larger sensor, but they don't have amazing zoom. Typically, they top out at the equivalent of 120 to 200mm. The ones that reach 200mm are too big to put in your pocket.

I went through the process of looking for a pocket-sized camera that gives good image quality, specifically with concerts in mind for my low light benchmark. I bought a Canon S100 and have been very pleased. It offers a spotmeter and true manual control, both of which are needed for good concert work. It's about the size of a deck of cards, too, so it fits in a shirt pocket easily.

The digital zoom is actually quite useable, too, so maybe it does qualify as having amazing zoom. It goes to 485mm!

Here's one sample concert photo, shot at ISO 3200: http://www.flickr.com/photos/samfeinstein/81044631...

There is a series showing digital zoom among the other samples: http://www.flickr.com/photos/samfeinstein/tags/s10...