Charles I second the jupiters moons app for iPhone (or iPod). I used to scoff at apps thinking REAL programs demand a laptop!! Alas apps these days are super . There is nothing like having hand held info via a decent app like jupiters moons to say nothing of SkySafari. I am a convert. I think I was one of the last folks in America to finally get a smartphone and it just keeps getting better. At anyrate, jupiters moons is excellent. A more sophisticated app like SKYSAFARI contains the same info roughly but the immediacy of jupiters moons over ferreting out the info in safari is extra nice.