Taken directly from Wikipedia:
The term Wi-Fi, commercially used at least as early as August 2000, was coined by a brand-consulting firm called Interbrand Corporation. The Wi-Fi Alliance had hired Interbrand to determine a name that was "a little catchier than 'IEEE 802.11b Direct Sequence'". Belanger also stated that Interbrand invented Wi-Fi as a play on words with Hi-Fi (high fidelity), and also created the Wi-Fi logo...
Thanks at providing the background, Tesserax. I agree wholeheartedly that "Wi-Fi" is _handier_ than "IEEE 802.11b Direct Sequence".
But in _my_ mind at-least, I shall think "Wireless Fidelity" when I hear Wi-Fi. :-)