It seems like I stumble upon subtle reminders that I am getting older quite frequently these days. Today it was iPhone’s fourth birthday.

I distinctly remember watching Apple’s demo video with my parents while home from college on my summer break. We huddled up behind my Powerbook G4 and watched wide-eyed in disbelief while inserting a few ”oohs” and “aahs” when appropriate. Four years later, these gadgets are the norm and tablets seem to be the new it-thing. In fact, if you don’t own some form of a smartphone, you are almost as rare as the PDA owners of the 90s.

While working on my feature, Mobile Commerce: The New Retail Therapy, for the July issue of CRM, I found the growing consensus among vendors, analysts, and businesses to be that mobile shopping is a phenomenon to stay. In fact, Forrester Research estimated that 53 percent of mobile customers will most likely increase their mobile spending budgets in 2011.

In addition, several experts agree that the smartphone may soon replace our physical wallets. The reason? “We are doing almost everything on a mobile device; that’s just the direction of the world,” observes Michael Fauscette, group vice president of software business solutions for IDC. “We are always connected. We have evolved into having the constant interactivity of the Internet, so it’s just natural that I want to take the next step and want to do some type of commerce, or I want some customer experience tied into the mobile device as well as other things.”

Well, shoot. I invested a lot of hard-earned cash in my Burberry wallet.