I’ve been testing the Nokia N80i (Internet Edition) for the past month or so. As I write this, I am at cafe in Buenos Aires. I have been trying to come up with a shorthand way to describe making a VoIP call from a wifi hotspot.
Voice over WiFi is too long, and too techy. So what about Spot Dialing? What do you think? If you like, pass it along.

"SpotDialing" not bad. Some other possibilities...."SpotCalling", "HotCalling",."CallFi"
Wi-Dialing, or Wi-Di. sPOTS, like "wifi spot" + "POTS".