I have two sons who served in the military (one for eight years, one at 13 years and counting) - respect for our flag and our anthem is ingrained in me.
When the anthem is played, regardless of the venue I stand at attention with my hand over my heart, my eyes on the flag. If it's a band playing it, or if the crowd is invited to sing along with the person at the mike, then yes...I sing the anthem. There are a few other people at football games and basketball games that also sing it.
Funny thing: I have noticed that as the seasons progress, more and more people are singing along with us few. I think some people are okay with singing it whenever, wherever, while others need someone else to be the first "brave" one to sing. The melody for our anthem is extremely challenging for even trained singers due to the crazy range it encompasses, so I understand why many people are reluctant to sing it. If you can't carry a tune in a bucket, no worries...sing it anyway if you feel moved to do so. Or simply stand quietly, hats off, and let the others sing it.
There's quite a bit of truth in many of these comments. Many performers will give their own twist to a song, but our national anthem should be recognizable. Some stylizing is fine, or group singing choral arrangements with different harmonies...but the version posted above renders the anthem virtually unrecognizable, as was Rosanne Barr's version a number of years back at a baseball game, or the version I heard "Xtina" perform a few years ago. If that makes me a hypocrite, so be it.