Today's lithium batteries wear out no matter what you do, but you can postpone the inevitable. Avoid heat and use the battery as little as possible. If you're going to be running on AC power for awhile, shut down or hibernate the computer, remove the battery, and work without it.

Spill coffee on your desktop keyboard, and you'll have to spend $15 on a generic replacement you can plug in yourself. Spill it on your laptop keyboard, and you could short out the motherboard. I'll admit that I use my laptop in cafes just like everyone else, but I put my tea as far from the electronics as my table allows.

You don't always need portability. When working at your desk,plug in a full-sized monitor, keyboard, and mouse. Not only does this get around the food and beverage problem discussed above, but it protects items far more valuable than your laptop--your arms, hands, and eyes. You can't set up a proper, ergonomic working environment with a small keyboard attached to a small monitor.

Before taking it on the road, pack the laptop properly. Depending on your carrying preferences, look for a carrying case, backpack, or shoulder bag with a padded section designed especially for a laptop. (I use a backpack because the even distribution of weight is better for my spine.)

When keys starts sticking, it's time for a cleaning. Shut down the PC. Keep it open as you turn it upside-down and very gently tap on the back so that crumbs fall out. Then use a can of compressed air (you can buy this at any computer store for a few dollars) to blow out whatever is still stuck. Be sure to read the instructions on the can, first. Then turn the PC upside-down and tap it gently again to get the last bits out.

If you can't see the email for the dirt, it's time to do a little cleaning. Start with a dry, microfiber cloth--the sort you get at an optometrist's office (you can also buy them at photo and computer stores). Move it in circular motions. Be gentle, but apply slight pressure on particularly stubborn spots.

If you still use Windows XP, your operating system expects you to perform a few more maintenance tasks than later Windows versions do. Defragmenting your hard drive, for instance, is automatically scheduled in Windows 7 and Vista but has to be done manually in XP (right-click the drive name in My Computer, select Properties, Tools, and choose Defragment Now).

You may not care enough about bug fixes and minor features to keep every single app on your hard drive current, but you'll need to keep Windows and a few major apps (such as your browser, your PDF reader, and your office suite) updated to avoid nasty security exploits. Fortunately, you can arrange to have all of these updated automatically.

Laptop batteries are like people--eventually and inevitably, they die. And like people, they don't obey Moore's Law--You can't expect next year's batteries to last twice as long as this year's. Battery technology may improve a bit over time (after all, there's plenty of financial incentive for better batteries), but, while interesting possibilities may pop up, don't expect major battery breakthroughs in the near future.

Squeezing every drop of juice out of a lithium ion battery (the type used in today's laptops) strains and weakens it. Doing this once or twice won't kill the battery, but the cumulative effect of frequently emptying your battery will shorten its lifespan.(There's actually an exception to this rule--a circumstance where you should run down the battery all the way. I'll get to that later.)