Aloft in the New Mexico sky wafts a huge hot-air balloon -- not the standard, graceful teardrop, but a giant replica of Carmen Miranda, fruit salad coiffure and all. It is an advertisement for a small Albuquerque art-importing firm, another indication of the rising interest in balloons as marketing tools.

"It's one of the most exciting ways to spend advertising dollars because it generates interest in the community," says Tucker Comstock, who, as sales manager for Cameron Balloons in Ann Arbor, Mich., can perhaps be forgiven for pumping up the business a little. "If you fly a balloon somewhere, there's a good chance it will get picked up by the local newspapers and TV stations."

Besides Miss Miranda, the company's other creations have included a representation of Snow White's cottage for a small mortgage company, and a pair of jeans with a 1,160-inch waist and a 1,198-inch inseam for Levi Strauss & Co. "The size and shape is limited only by the customer's imagination," explains Comstock.

Although product-shaped advertising balloons have long been used in Europe, they have only recently begun to catch on in this country. The Ann Arbor company has been an independent licensee of Cameron Balloons, based in Bristol, England, since 1974. Currently, there are fewer than a dozen hot-air balloon manufacturers operating in the United States.

They have, however, been quite busy in recent years. ln the late 1960s, there were fewer than 10 hot-air balloons in the United States. Today, that figure has soared to nearly 3,000, with about a third of them carrying a commercial message.

The simplest approach is to use a traditionally shaped balloon or blimp with a slogan or company logo printed on the side. With a three- to four-person gondola attached, a standard balloon runs about $20,000. Custom-shaped, manned balloons start at $45,000.

Less expensive, unmanned inflatables are also available in myriad custom-made varieties. Filled with cold air, they are generally tethered to the ground or a billboard. A typical 10-foot-by-30-foot inflatable starts at about $5,000. Aside from advertising, some companies use them to add flair to special events, such as sales meetings or company picnics.

The demand for these small inflatables has also been picking up lately, as evidenced by Impact Inflatables Inc., of Marblehead, Mass., which began operations in 1981 with $65,000 in revenues for its first 12 months. In 1983, it racked up $125,000 in sales and expects to reach $500,000 in 1984. Meanwhile, industry sales of cold-air inflatables in North America and Europe have grown from $6 million in 1982 to $11 million in 1983.

Not bad for ads that come with strings attached.