ìkewlî is the network geeks word that has the same meaning as gnarly (surfer culture), sick (teen subculture), wicked (american movies). That is, it can mean something magnificent, or something so retarded or mind bendingly stupid as to be beneath contempt and varying degrees in between. Not normally used in executive meetings or board level presentations. Most commonly observed when a colleague shows you a neat Cisco IOS CLI trick, or a new piece of OS X software.
Usually pronounced ìqueue-wellî, and the more kewl something is, the more emphasis on ìQueueî there is. Derogatory invocations typically involve substantial quantities of dripping sarcasm.