Hi everyone,
To make it easy to upload your images to Commons we created a campaign, see https://commons.wikimedia.org/wiki/Special:UploadWizard?campaign=Wikimania20... It only accepts a default license and automagically adds a category so that the images end up in https://commons.wikimedia.org/wiki/Category:Wikimania_2013
Happy uploading!
Maarten
Ps. Mobile users can of course use the Commons mobile app to upload from their phones directly at https://commons.wikimedia.org/wiki/Commons:Mobile_app/Download