iPod

Enable disk use on your iPod classic or earlier and use it like a USB drive. And sync your iCal events and Address Book contacts with your iPod. With .Mac, you can also use your iPod as a backup destination in the Backup app.

Display Adapter

Plug into a larger display or a projector with a DVI-to-VGA adapter (MacBook Pro), a Mini-DVI-to-DVI adapter (MacBook), or a Mini-DVI-to-VGA adapter (MacBook). All are $19 from Apple.

USB or FireWire External Hard Drive

Let Time Machine do backups on the road. And you can even boot your Mac from a FireWire drive in an emergency. (Shown, LaCie Rugged All-Terrain, $89.99 and up)

Spare Battery

Buy a spare battery ($129, www.apple.com) for your MacBook and charge it before you leave the office. Better yet, pick up a TruePower Extended-Life Battery from FastMac ($99.95, www.fastmac.com) and get slightly longer battery life for less money.

MagSafe Airline Power Adapter

Use a MagSafe Airline Adapter ($59, www.apple.com) to take advantage of the laptop power jacks in many airline seats.