The University Library has recently started placing QR codes on the bookshelves. These take you directly to the e-book of the corresponding title. The offer is intended for the case that all copies are borrowed or a newer edition is available as an e-book. Just browse through the shelves and try to find a QR code. Once you have found one, scan it with your mobile device and you will be taken to the e-book. Have fun with it! By the way, the range is constantly being expanded.