AN FRANCISCO, Dec. 5 ? The wireless technology known as WiFi, which allows users of personal and hand-held computers to connect to the Internet at high speed without cables, got a significant stamp of approval today when AT&T, I.B.M. and Intel announced a new company to create a nationwide network.

The unruly technology, which has largely been a playground for hackers, hobbyists and high-technology start-ups, is already sprouting mushroomlike in coffee shops, bookstores, airports, hotels, homes, businesses and even a few parks.

The new company, Cometa Networks, has set ambitious goals for itself: to deploy more than 20,000 wireless access points by the end of 2004, placing an cable-less high-speed Internet connection within either a five-minute walk in urban areas or a five-minute drive in suburban communities.