Libraries have become increasingly interested in studying the use of spaces within their buildings. Traditional methods for tracking library building use, such as gate counts, provide little information on what patrons do once they are in the library; therefore, new methods for studying space usage are being developed. Particularly promising are mobile technologies, which make it possible to directly observe and track user behaviors throughout library spaces. We found that observation combined with mobile technologies enabled the library to assess user study behaviors and space usage patterns anywhere in the library. Observations were tracked using an iPad with two different types of mobile apps, CloudOn and Counter+. The results were compared to the more traditional statistics gathered by the study room reservation system. The findings showed that the mobile observations more accurately reflected actual library usage and provided additional details on specific study behaviors such as studying in groups and using technology while studying.