I am meeting MusicGremlin co-founder Robert Khedouri at a Manhattan Starbucks, where Sheryl Crow's new CD is for sale. A compact disc - what a quaint relic. I ask Khedouri if I can simply download the title track -- right here, right now -- to a MusicGremlin.

He hands me his company's new Wi-Fi MP3 player. The device connects instantly to an online song library, and I can download a tune in about 30 seconds. "Let's go somewhere that has free wireless access," I suggest.

We start walking in search of one of the nation's 6,000 gratis hot spots, among them libraries, malls, and eateries. When we finally hit pay dirt, I download my wish list: "Gold Digger" by Kanye West, "After Midnight" by Eric Clapton, and Billie Holiday's "God Bless the Child."

Khedouri then suggests we switch our MusicGremlins into community mode. Now my player is connected to his player. Had a Gremlin-toting stranger passed by, his on-screen name would have shown up. In community mode, I'm able to see the title of the song Khedouri is listening to, "Daughters," by John Mayer. He beams it to me, and I can choose whether to buy it. I select "accept" in a dialog box, and my MusicGremlin's song library grows fatter. Had this been for real, my credit card bill that day would have been $5 higher.