Looking for a unique way to promote your next event? What about a 6-story-high golf ball?

StratoSphere, a translucent, transparent, illuminated balloon, features 2,000 square feet of floor space underneath — enough room to accommodate 250 people with room left over for a speaker's podium, band area, bar, or live entertainment. Absolute Hollywood (www.absolute-hollywood.net), a Houston-based outdoor entertainment/promotions firm, rents the balloon.Other balloons, some as small as 30 feet in diameter, come without bases so that they can fit inside an exhibit hall, and with revolving doors in the base so they can be used as a VIP lounge.

StratoSphere's marketing value lies not only in its size, but in the fact that sponsors' logos can be projected onto the inside of the balloon skin, while the outside can be designed with the dimpled look of a giant golf ball. To really gain attention, the huge ball can be made to look as if it's spinning.

The firm has designed balloons for events as diverse as the NCAA final four basketball tournament and the debut of the French-language Yahoo! Web site — where the balloon was climate-controlled for the chilly late November weather in Montréal. Rental costs average $20,000, depending on length of use and size. Companies can also sell advertising space to sponsors to recoup part of the rental cost and project their logos onto the sphere.