Mobile users are either repetitive, bored, or urgent
In a recent article Google Lays Out Its Mobile User Experience Strategy (opens new window). In it they bring attention to something we don't often think about. Mobile users are either repetitive, bored, or urgent.
Users who have time on their hands. People on trains or waiting in airports or sitting in cafes. Mobile users in this behavior group look a lot more like casual Web surfers, but mobile phones don't offer the robust user input of a desktop, so the applications have to be tailored.
Request to find something specific fast, like the location of a bakery or directions to the airport. Since a lot of these questions are location-aware, Google tries to build location into the mobile versions of these queries.
Keeping these three user types in context can really help shape your project. If your site doesn't accomplish your users goals they likely won't come back.