SIKESTON, Mo. -- Some call it hoarding. Others insist it has to do with sentimentality.

But the truth of the matter is more and more people are running out of room to put their stuff.

And in answering Americans' plea for help, the self-storage business has grown into a $10-billion-per-year industry.

Todd Curtis of Todd's Towing Service and Discount Storage says the business he manages lets customers store practically anything that's not illegal, hazardous or explosive.

"A lot of people have a lot of things they need to store because they're moving, traveling or they're college kids," said Curtis, manager of the storage business which opened two months ago.

Curtis said the business stores "a little of everything," including heavy equipment, cars and furniture.

Once just a slot of space, some of today's multi-storied units come equipped with computerized climate-control and state-of-the-art security systems.

The number of self-storage facilities in the United States grew nearly 9 percent between 1998 and 1999, from 27,535 to 29,955, according to the latest figures from MiniCo Inc., a Phoenix, Ariz.,-based company that tracks and publishes industry data. In 1990, there were 20,000 self-storage businesses and in 1982, just 10,000.

The average occupancy rate at the facilities, which offer some eight million individual storage units, was 86.9 percent in June 1999, rising from 85.1 percent the year before.

Chris Shanle relies on the storage unit he's renting to protect one of his most prized possessions. "I store my vehicle in it," he said. "If it wasn't for a storage unit, it would have to sit out in the weather."

Shanle said he likes storage units because they're sealed so nothing can get into them.

"Twenty years from now you could go back to whatever you're storing in them and it would be the same," he said.

Like many, Terri Matthews keeps her can't-bear-to-part-withs in a large storage facility behind her house.

"When we moved, I didn't have any storage. Older homes didn't have closets because they were taxed on closets as a room in the house," she said. "The people that own the house have things stored in their attic. So what was purchased as a storage shed to keep outside tools and lawn equipment, has now become my 'treasured attic.'"