A technical report is now available on our SpotCode visual tag system, and includes a user study lead by Eleanor Toye Scott which tested its benefits against conventional mobile interfaces. The work demonstrates how camera-phones can be used for "point-and-click" interactions with visual tags in the real world, measuring both pointing speed and accuracy. We built a complete client/server framework to make it easy to develop applications using this technique, and validated it with prototype applications. The results showed that even novice users could quickly and accurately interact with site-specific mobile services using just their camera phones and public displays.