I SHARE MY personal wifi hotspot at industry events. I keep it "open" and listen for people to exclaim, "I've found Topgold!"
I think it's important to share 3G data connectivity, especially in venue where the house wifi creaks and groan from too many video streaming sessions. Weeks later, friends have shown me their phone screens where my Twitter name sits as an SSID that they graciously used. It's always a conversation starter and I have to think it's also a method of branding.
[Bernie Goldbach's free and open wifi will be online at #cesicon, Ireland's largest gathering of educators.]