Hush, little baby

Unless you've explored your iPod's every nanny and crook, you've likely missed its sleep timer. On a recent clickwheel iPod you'll find this option by following this path: Main -> Extras -> Alarms -> Sleep Timer. On clickwheel iPods a little older--first- and second-generation iPod nanos, for example--follow this path: Main -> Extras -> Clock -> Your Clock -> Sleep Timer. On early clickwheel iPods (an iPod mini, for example), go to Main -> Extras -> Clock -> Sleep Timer. And with an iPod touch or iPhone, you use open the Clock application, tap Timer, set a time, tap When Timer Ends, and in the screen that appears, tap Sleep iPod. Sleep timers on clickwheel iPods run from as little as 15 minutes to as many as 2 hours. An iPhone or iPod touch's timer can run for up to 23 hours and 59 minutes.

The way it works is pretty simple. Just set the sleep timer on your iPod, plug the iPod into something that makes noise (it may be rough to sleep with headphones on so a set of speakers with an iPod dock or audio input jack is the more comfortable option), and go to sleep. When the timer expires, the iPod shuts off. Some iPod-compatible clock radios include sleep timers of their own so you don't need to muck with the iPod or iPhone's internal timer.

Some people (I'll include myself in their number) like to have sound playing all night--ambient soundtracks such as the ocean or rain, for example. The point of these tracks isn't to listen to them develop over time. Rather, you just want them white-noising along in the background. And because you do, you just need them to repeat over and over again.

That's easy to do. On any clickwheel iPod go to Settings -> Repeat, and push the Center button until the Repeat command reads "One." Then navigate to the track you want to listen to and start it playing. It will repeat until you stop the iPod from playing (unless you've set a sleep timer, in which case the iPod will shut off when the timer expires). With an iPod touch or iPhone, locate the track you want to play, tap on the screen to produce the timeline, and tap on the Loop icon just below and to the left of the timeline until it shows a 1. This indicates that the currently playing track will remain the currently playing track until you stop it.