Many websites are adapting their content for users who are accessing the Web using smartphones and tablets. The growth of this Mobile Web has required web archivists to change their practices in order to collect this ephemeral web content. We have created a tool called MobileFinder which can be used to automatically detect mobile pages when given the URL of a desktop web page. We used this tool in an experiment to gauge what techniques popular websites are currently using to expose mobile content, and we incorporated the tool into Heritrix to demonstrate its usefulness to the web archiving community.