I don't mean to be a jackass, but the next time someone shows up to a small gig using a dSLR and kit lens, taking an obnoxious number of pictures using the pop-up flash... I will ask how their pictures went, and gush about how they must be so awesome!
Seriously. There's a reason why flash photography is not allowed in venues. Not to blind the band, but to prevent people from taking crap pictures. Remember, on-board flash = crap! And if you can obviously see on the playback screen that your pictures look like crap, taking another one (and 40 more thereafter) using the same technique must probably give you better photographs. What's that saying about teaching the pig to fly? Something about annoying the pig.
Time to get some pho and clear out my head.