Technology for planning falls into three broad categories.

Software for desktop and laptop computers includes products that create calendar entries, to-do lists, and project schedules.

Also look for contact managers, which bring to mind the old-fashioned rolodex. With this software you can store names, addresses, and phone numbers. Also keep detailed notes about clients, customers, job contacts, or anyone else you want to remember.

Hand-held devices use the same kind of digital technology as desktop computers. One of the first was the PalmPilot--essentially, a computer that fits in a pocket or purse. The newer models can store up to 1500 to-do items, 6,000 addresses, and five years of appointments. Look for similar devices from competing manufacturers.

Instead of coming with a keyboard, many hand-held devices operate with a stylus--a tool that looks like a pencil and allows you to write directly on the screen.

You can always use real pencils to write on paper resources--traditional printed calendars.

Note that the distinction between print-based and computer-based materials is fading. Many companies that sell paper calendars also offer computer-based versions of their products. With this software you can design calendars in several formats (daily, weekly, monthly, yearly) and print them out.