The company once best known for its Macintosh computers said in January that it had sold more than 10 million iPods.

Most of the time, of course, the iPod is used for its primary function: playing digital music.

But the growing ranks of iPod users are increasingly tweaking their devices to perform all sorts of cool and useful tricks. Meanwhile, Web sites, magazines and books are cropping up to offer hints about new things you can do with your i-Pod.

A new book, The iTunes and iPod Garage, by Kirk McElhearn, suggests that you can use your iPod as a flashlight in a pinch.

''Yeah, it sounds weird,'' McElhearn writes, ''but that backlight is pretty powerful. If you ever get lost in a cave or stuck in a staircase during a blackout, the iPod can save your skin.''

Set the backlight for 10-second intervals to preserve battery life. Or spend $20 on flashlight and laser pointer attachments for your iPod from Griffin's iBeams at http:// www. griffintechnology.com/ products/ibeam.

A fabulous collection of iPod tricks can be found at the iPodLounge at http://www.ipod lounge.com/tips.php. Here's one you'll want to try: setting up your iPod to put you to sleep.

The author suggests downloading 10-second sound file samples from http://www.dog star.dantimax.dk/testwavs/ and then replicating them with Quicktime software until you have a 30-minute segment. Convert that to the ACC file format, and upload to your iPod. ''Set the iPod to Repeat One, and off to sleep you go,'' he says.

Not to be outdone, ExtremeiPod.com points out a way your iPod can wake you up, too.

To set up the iPod alarm clock feature, go from the main iPod menu to Extras and then Clock. When you see the current time, go to Alarm Clock, and choose ''alarm.'' Press the iPod ''select'' button until the alarm is set to ''on.'' Choose ''time,'' and press "select" to set the wake-up hour. Then choose ''sound,'' and pick a song or playlist.

Be sure to have an external speaker connected to your iPod for full effect. Details at http:// www.extremeipod.com/ article2/0,1759,1728275, 00.asp.

Want more? Here's a tip for hacking the Pepsi iTunes promotion.

As you may know, Pepsi is hiding a coupon for a free iTunes song download under the cap of one out of three Pepsi bottles. The authors of a Web site at http://methodshop. com/mp3/articles/hackpepsi/ have devised a strategy for figuring out which ones have the coupons.

Note: This technique does not involve removing the cap before purchase, as some folks have been doing. Instead, it's a matter of tipping the bottle to peek under the cap.

You've got to tip your cap to them for that one.