Toshiba's tiny high-capacity hard drives are hitting new highs — the firm is announcing 10GB and 20GB versions of the series.

Measuring 1.8in across — two pound coins side by side — the double-sided, single-platter drives premiered at 2GB in May 2000 and expanded to 5GB in June 2001.

Toshiba has doubled the capacity in the 10GB model and quadrupled it for the 20GB model by adding a second double-sided platter.

At last week's CES show in Las Vegas several companies including Creative, RCA and SonicBlue (the Rio people) unveiled handheld music players that use 2.5in laptop-style 10GB and 20GB hard drives in paperback book-size devices.

The new Toshiba drives could match that storage in players about half as large. Drives of 1.8in are the optimum size, says Toshiba spokesperson Amy Dalphy. "There are a lot of [players with] 2.5in hard drives out there, but they're big."

The most notable application of Toshiba's 5GB drive is probably the Apple iPod MP3 player (pictured), which can store upward of 1,000 songs. Though neither company will confirm that the iPod uses Toshiba's drive, representatives of both companies acknowledge Toshiba is the only one producing a 5GB drive small enough to fit in Apple's music player.

Music players are only one application Toshiba is banking on. Gigabytes of storage would also allow handheld devices to contain video files, for example. While Delphy can't name customers, she says Toshiba is working with a number of companies on a variety of product ideas that could use Toshiba's tiny drives.

Toshiba will ship its new 20GB drive in volume in February and the 10GB version will follow in March.