Another five must-have freebies for iPhone, iPod Touch

Tuesday's roundup of killer freebies for Windows reminded me that I haven't covered iPhone/iPod Touch freeware in awhile, so here's another list of must-have apps that won't cost you a penny:

• Air Sharing Turns your device into a portable, wireless hard drive and document viewer. Note: this jewel will eventually be priced at $6.99, but for the next few days you can snag it free.
• Graphing Calculator Why spend big bucks on a graphing calculator when your iPhone/touch can do the job for nada? This uber-handy tool offers functions ranging from absolute value to tangent.
• Hanoi A beautiful rendition of the classic Towers of Hanoi game. The object is simple: move a stack of disks from one side of the board to the other. I couldn't put it down.
• Instapaper Free When you're browsing on your PC and come across a Web site (cough *Cheapskate* cough), blog post, news item, feature, or whatever that you want to read later, just click the Instapaper bookmarklet. Then fire up the Instapaper app on your iPhone, and presto: there's the Web page. Genius!
• White Noise Having trouble getting to sleep? White Noise offers an assortment of ambient sounds--waves, rain, wind chimes, etc.--to help you drift off. And there's a shut-off timer so you don't wake up to a dead battery.

If you like this list, be sure to check out my original roundup of iPhone freebies and the sequel. In the meantime, hit the comments and vote for your favorite no-cost iPhone apps.