As far as mobile phone applicaitons go it is hard to find anyting more Web 3.0 than SKOUT. SKOUT includes many of the key elements we believe will make Web 3.0. Firstly it is ground on the Facebook API and builds a dating site out of it. Web 3.0 will be about connecting cloud services to create new solutions. SKOUT certainly does that.
SKOUT enables one to access social data not only by semantic characteristics, but also by location. People have to join SKOUT so these searches are not violating privacy (we assume)
And SKOUT does deliver. You can use SKOUT to meet people in local areas for anything from dating to just chat, though we assume dating is a primary object of it. Regardless of what you think of online dating you must see that there is demand for such a service to be geo-located and driven from a service like Facebook, Twitter or Foursquare where lots of people already have identities and personal data created.
But the implementation just feels cheap and desperate to make money. Its not just the endless adds running down the bottom (the new pop-up add) but features like the ability to send Wink Bombs that makes SKOUT look like a ugly preview of what Web 3.0 could be.