What exactly is that, you might ask? Well all activities have conditions that make them better or worse, the most obvious is the weather…you probably wouldn’t go swimming in the Atlantic in canada in january. But there are other datapoints as well, such as recommendations, traffic predictions, netflix recommendations etc.
I would like a very clean simple to use interface where users keep lists of activities they want to do, and plan trips using collaboration tools. For instance, I could list that I am interested in symphonies, wakeboarding, and roller derbies.  And when one of those events was coming up, I could get a reminder email listing off upcoming events for the week/month. I could synch artists from iTunes, and check to see if any concerts nearby are featuring artists that you listen to. And events would have pertinent data, weather information, traffic predictions (especially when competing large events are occuring at the same time in a close proximity), and tips and feedback from members who have been to the event before “make sure to bring a blanket!”.

In addition to large events, you could even add your own small road trips, and general activities. Like wind surfing, but want the weather to be over 70 degrees for a consecutive month first? Great, we’ll let you know when the water’s good!  So if you were stuck on what to do, you can focus on what you would like to do, instead of having to micromanage a whole lot of extra data.

You could plan other minor events, such as going to movies, dinners, or board games. You can leave yourself reminders of what works and what doesn’t “send out invites no later than one week before” with additional community tips. The end goal would be to make the service so useful, that the user wouldn’t want to plan anything without it. We could link into twitter, facebook and a variety of other social networks to coordinate communications and invites, and synch to calendars. Synch with netflix rankings to recommend movies in theaters.

Money would come from sponsored ads from activity planners, similar to mint.com’s mantra, we would want all ads to be targeted specifically to be helpful to users. It would take alot of tweaking to get right, but I think would be very useful.

Current competition:

Yelp – Has a good fanbase, and lots of reviews, not necessarily activity focused, but that may come in the future.

Hype Machine – Concert recommendations

Eventful – Looks like the serve as a directory for local events, don’t know what type of planning they have, you can subscribe to rss feeds.