Since the turn of the century, one of the hottest topics in the IT world has been the coming mobile revolution. While there's been some arguing over the details, the fundamental tenet of the mobile revolution is that lots and lots of people will start accessing web content from handheld portable devices instead of using a traditional laptop or desktop. For evangelists of the mobile revolution, this shift is the logical conclusion of market penetration and growth rates. Forrester Research estimates that there are about a billion computers in the world. In contrast, the International Telecommunication Union estimates that there are about 4 billion live cell phones in circulation today. That's two-thirds of the world's population. As more of these devices come online, making sure that resources--such as OPACs--are compatible with these devices becomes imperative. In this article, the author takes a look at how typical OPAC offerings from SirsiDynix; Innovative Interfaces, Inc.; and AquaBrowser appear on BlackBerries, iPhones, and Windows Mobile-compatible devices. He brazenly passes judgment on both the OPACs and the phones involved, chats about some other systems, and then looks at how one can test his or her own library's site. (Contains 5 figures.)