On my way to Tuesday night’s U2/Muse concert in Atlanta, I realized I had forgotten a) my cellphone and b) decent camera.

I later joked on Facebook: “America was deprived of an evening of live tweets, photos and FB updates. Epic social media fail. . . or probably a blessing for y’all.”

Actually, forgetting my cellphone was probably a blessing for me as well. While I thoroughly enjoyed watching the concert, I was equally mesmerized by the second ongoing show — fans taking photos and shooting video with their cellphones and digital cameras. In some cases, fans were watching just-recorded video while ignoring the live performance continuing onstage.

Today, I relived the concert watching fan video of the show, with amazingly clear visuals and sound from the cavernous Georgia Dome — some of it shot 100 yards from the stage. The sound was clearer than what I heard last night.

U2’s Bono was apparently watching the cellphone show and late in the concert asked the audience to light the darkened arena with their phones while he sang “UltraViolet (Light My Way).”

What social media lesson can a small business or professional learn from this? It’s an obvious case study in how people are consuming entertainment and information in a digital age. People are producing — and consuming — content on the go.

YouTube reported a 400 percent surge in video uploads after the iPhone3GS was released. Ironically, while the U2 tour is sponsored by BlackBerry, everywhere I turned I saw iPhones in the crowd. There were just as many 50-plus types using their phones as 20-somethings.

Look for opportunities to share content and connect with your potential customers through mobile devices, especially at events. But whatever you do, don’t spam cellphone users. Active mobile users are even less tolerant of one-way marketing than those on a desktop/laptop.