{Update! New List! New Post! See the new list of iPhone applications I actually still use in this post, from September 2009.]

For 99 cents I downloaded Ocarina, an app from Smule that turns an iPhone into a version of that ancient flute-like instrument. You press glowing "finger holes" on the touchscreen and blow into the microphone to play [Video].

That's fun, but Ocarina does more than that. The app also uses the location software and a Google-Earth style globe to let you rotate the earth and listen to others play on their phones around the world. As they play one by one, visual images of the notes stream upward, as you watch from space. Around the globe, patches of glowing white show what are apparently concentrations of signals, particularly on the coasts of the United States and in Europe. One soloist sent a lonely tune up from an island of Hawaii. It seems the perfect instrument for the job. Halting, ghostly renditions of "Amazing Grace," "God Rest Ye, Merry Gentlemen," "Happy Birthday," and "Ode to Joy," reach for the stars one by one. You can click a heart to show your appreciation for the particularly talented ones. It's just cool. You feel connected with other musical beings on the planet. GPS broadcasting! Imagine what else could be broadcast through those mikes.

The Smule site advises, "For best results, blow softly, as if you're blowing kisses." It insists on calling the iPhone "your ocarina."

My daughter and I each gave it a shot. Our efforts sounded more like free-form jazz. Somehow I missed this app when it first came out earlier this month, and my older-generation iPhone apparently required the 2.2 firmware update first. But it's one of those apps that is sure to wow a friend, divert a fidgety kid or pass the time. I am sure some talented musicians will find ways to amaze us. I recently added it to my list of favorite third-party iPhone apps.