We show how modern mobile phones (Weiser's tabs) can interact with their environment, especially large situated displays (Weiser's boards). Smart phones' emerging capabilities are fueling a rise in the use of mobile phones as input devices to such resources as situated displays, vending machines, and home appliances. Mobile phones' prevalence gives them great potential to be the default physical interface for ubiquitous computing applications. We survey interaction techniques that use mobile phones as input devices to ubiquitous computing environments. We use smart phone to describe an enhanced mobile phone. Our analysis blurs the line between smart phones and PDAs such as the Palm Pilot because the feature sets continue to converge.