Running out of room at the office? Can't face a move? Take a cue from David Roberts of Silicon Valley's FireDrop: move your neighboring company and take its space.

Roberts cofounded his company, which created a new communications platform known as the Zaplet, in Redwood City, Calif. -- an ideal location for recruiting engineers. "It's in the center of the world for the Silicon Valley -- equidistant from San Francisco, San Jose, and the East Bay," he says.

Roberts leased 25,000 square feet of space on a second floor in a brand-new, 12-building development, assuming that he'd be able to lease more space on the floor below if he needed it. "But within 90 days all the other space was taken," he says.

With his company growing rapidly, Roberts needed square footage for his new hires, and he needed it fast. But he also wanted to stay put in order to keep attracting good talent.

More important, he didn't want to split the team between two locations.

So Roberts subleased some space in another building within the same development. Once it was secured, he negotiated with one of his downstairs neighbors about taking over that company's offices. Roberts paid to move the neighbor into the other building and then occupied the space downstairs.

At 150 employees and growing, FireDrop may negotiate a similar deal with its two other neighbors. "The great thing about dot-coms is that they either get bigger or they disappear," says Roberts, who expects to have the whole building full of FireDrop employees by summer.

All the moving around has been a lot of trouble, he says, much of which could have been avoided if he'd had more confidence in the company's prospects back when he first leased space. "I wish we were smart enough at the beginning to have realized that we'd do very well," he says.