Instagram is one of those early adopter favorites that quickly crossed the chasm to more mainstream users, at least within my social network. Take that popularity, mix it with an apparent desire to buy shirts, and it was inevitable that someone would use the Instagram API to create wearable mashups. In fact, there are at least three such services, each with its own twist.
You've spent years sharing your life on Facebook, Twitter, Foursquare, and recently adding photos to the mix with Instagram. If you're like me and many others, sharing this stuff also serves as a means of archiving things to be able to easily look back later and say, "remember that? That was great."