Here's the (5 minute) video of my presentation last week at the Ignite Where event, part of the Where 2.0 conference. It was a great week - will be posting lots more on my impressions over the next couple of days.
This clip is an extract from the O'Reilly video of the Ignite session (under Creative Commons license) - this starts at around 35 minutes in.
P.S. No fish in this one :) !!