IO Data likes their external hard drives.
These use a "slim" case, and go up to capacities of 300GB. They're also fanless, which I guess means they're silent besides actual drive noise.

IO Data Device Corporation will release the "HDH-U" series in the back part of May, which is a slim-case external HD series. Supported operating systems are Windows 98, ME, 2000, XP, as well as Mac OS 9.1x, 9.2x, X 10.1 ~ 10.3.3.

The price of the 120GB "HDH-U120" is 18,700 yen, the 160GB "HDH-U160" costs 22,000 yen, the 250GB "HDH-U250" costs 33,300 yen, and finally the 300GB "HDH-U300" costs 42,200 yen.

When connected using the USB 2.0 interface, a LED o­n the front of the drive will light up blue. When connected using the USB 1.1 interface, this same LED will light up green, allowing the user to recognize the drive's operational mode.

Also, rather than using a fan, the device uses an "airflow form" which uses natural heat radiation from the bottom of the drive to the top. When stored horizontally, the drive will radiate heat from the aluminium panels o­n the sides.

The size of the drive is 45 x 193.9 x 170.9mm (W x D x H).



Inspired by:
http://pc.watch.impress.co.jp/docs/2004/0427/iodata.htm

News Release:
http://www.iodata.jp/prod/storage/hdd/2004/hdh-u/index.htm