Should you ever need to convince Mr. Van Winkle that the iPhone he's recently heard so much about truly is a miracle worker, take him down to the local drinkery, wait for a song to start playing, fire up , tap Tag Now, point the iPhone's mic at the music's source, and observe the shock on his face when, scant seconds later, the name of the song appears on the iPhone's screen along with links for watching associated YouTube videos, browsing reviews, viewing the artist's biography and discography, and, in some cases, displaying the song's lyrics. Shazam gets far more than it misses and is an amazing demonstration of the power of the iPhone coupled with a remarkable audio analysis algorithm (Free; ).

You either get Twitter or you don't. For those who do, the iPhone and Twitter were made for each other: Twitter's microblogging service lets you post short, on-the-go messages for others to read, and the iPhone is an easy-to-use, always-connected communication device you're likely to have with you all the time. While there are scores of iPhone Twitter clients available, (Standard, free; Premium, $4; ) and ($3; ) have earned spots among on our list--the original Twitterrific for being the first really good iPhone Twitter client, and Tweetie and Twitterrific 2 for subsequently setting the standard for how great such an app's interface and functionality can be.