HP is entering the growing market for pint-sized computers targeted mainly for pint-sized customers with the introduction of the new HP 2133 notebook, priced at $500.

Hewlett-Packard joins Intel and Asus in market of the new miniaturized laptops for surfing the Internet and performing other basic functions like word processing.

Intel has labeled them "netbooks," and it expects more than 50 million netbooks to be in circulation by 2011.

HP executives say their new machines, which go on sale later this month, are an important piece of the company's effort to build market share in schools, where machines had to be smaller and cheaper without losing too many functions.

The companies also expect adults to cotton to the idea of buying two laptops - a lightweight one just for Web browsing on the go and the full-power machine for the home or office.

HP's foray comes in the form of a new computer called a "Mini-Note" that weighs less than 3 pounds with a screen that measures 8.9 inches diagonally. The machines start at under $500 for a Linux-based model. Prices go up for Windows Vista models with faster processors.

The processors HP is using are made by Via Technologies and come in clock speeds up to 1.6GHz. The inclusion is a big win for Via, which trails Intel and AMD by a wide margin in the microprocessor market.

HP executives say the only major feature its Mini-Note lacks is an optical drive for ingesting DVDs and CD-ROMs, which can be bought separately.

The Mini-Note will compete primarily with Intel's Classmate PCs - which are designed by Intel and feature Intel chips but are built and branded by other companies - and Asustek's Eee PC.