Despite all the excitement over flashy applications like mobile games and location-based social networks, iPhone owners are actually more interested in checking the weather, according to a survey from Compete. At the same time, when it comes to individual apps, it looks like Facebook is the most popular.

Compete’s survey is compelling, because although Apple occasionally releases its own lists of the most downloaded apps, it hasn’t published any official numbers on usage. In some cases, the download data and the usage data are pretty similar — for example, Facebook is both the most-used app and the most downloaded-one. But there are also plenty of apps that users download and then abandon, as last February’s report from analytics startup Pinch Media suggests. So the fact that users check the weather again and again, even as the novelty fades from other apps, is information that may be useful to advertisers. (I’m less optimistic that there’s a huge opportunity for developers to create a cool, new innovative weather app, although I’m willing to be surprised.)

At the same time, I found the survey, at least as summarized in MediaPost (MediaPost received a preview copy, though I’ve asked for one too), to be rather frustrating. There’s some apples-and-oranges comparison going on here, since Compete or MediaPost don’t separate the types of apps people said they use most from the specific apps they’re using, but rather combines them into a list of “the more than 100 individual apps or types of apps cited by users.” That’s why you get a confusing list that goes from weather apps in general (39 percent), to Facebook (25 percent), to game apps (20 percent), to the Weather Channel’s app (13 percent), to music apps (more than 10 percent). To me, that leaves a lot of questions unanswered, most pressing among them, how social networking apps did as a category. The article doesn’t say, only noting Facebook’s numbers and MySpace’s rather paltry competition (2.4 percent).

It’s also worth pointing out that 60 percent of iPhone users say they seek out apps on their own rather than just relying on lists of the most popular apps or on recommendations. That means there’s hope for your app to get discovered, even if you don’t get a ton of publicity. Not that publicity hurts.

Meanwhile, AdMob’s Jason Spero just wrote a guest column for us about why developers are so excited about the iPhone.