Toshiba is showing off the latest version of its fuel cell for portable devices, but problems with the new technology mean it will not be commercially available until 2005.

Fuel cells offer the promise of a powerful, long-lasting and very cheap power source in a tiny package. A number of companies have created fuel-cell designs, but none has made it to the production phase.

Read more: CNet News (http://news.com.com/2100-1041_3-5086066.html?tag=st_lh).