The natural logarithm of 2 is only described so succinctly because that number (and related ones) were so common and useful that we introduced a shorthand to denote the limiting process which tends to it. I think you'd find that, were the definition expanded completely, that its description is not so succinct after all. :)
I remember these guys from SXSW and I'm happy to see they got some financing.
Localmind is a very cool concept with a lot of potential but it needs thousands of users in every city for the app to be useful. During SXSW, they got precisely that level of density and the omniscience-as-a-service vision became very clear to me.
Intriguingly, because Localmind uses check-in services to passively acquire location data, it doesn't require users to actively use it in order for density to accumulate in the service.
