This area of search is notoriously difficult to serve well using a standard search engine, like from Google (GOOG) or Yahoo (YHOO). Most users, myself included, hop around to a multitude of bookmarked sites which list interesting events, as well as track related email lists in the hopes that we are presented with a reasonable representation of what's going on. It's actually a lot of work, and who knows how many cool events slip through the cracks using this form of "manual search". Worse yet, if you travel somewhere (even a short drive), most of your information is no longer relevant to your new locale.
In a way, almost all problems with search of "what's going on?" and "what to do?" can be summarized as contextual problems. One such problem with generic search engines is that they don't understand the context of the user (what they're trying to find). As a consequence, the user is deluged with irrelevant content. Another huge problem is that crawled content has a lot of arbitrarily formatted yet helpful planning information which needs to be contextualized, before being presented to a search user. For examples, location, phone numbers, and event dates and times are key pieces of info which need to be presented and factored into the search, but are likely listed in very arbitrary ways which need intelligent "contextualization" by the search engine. Goby aims to solve these kinds of problems. And it does it with an uber-simplistic user interface.
Besides this search vertical being incredibly under-served, it should also be very monitizable for Goby, as the net result of "what to do" searches is that people go places and spend money. I would think their search advertising premiums would be quite good. Google, take note...
Disclosure: no positions