The keynote speech at a recent Intel Developer Forum was on context aware computing driving the future of computing. PCMag has an article about it. The basic idea is to enhance devices so that they can act more like personal assistants and less like PDAs. The examples range from the rather outre such as using a EEG headset to take information directly from your brain, to a smart remote control recognizing who is holding it and altering your viewing experience, to more mundane examples such as sensing human gait and using GPS to determine your location in a smartphone.
It had a strong hardware focus (as expected), and didn't appear to mention existing location based search with smart phones. Instead, they demonstrated a prototype of Fodor's Travel application that combined location awareness with other data its learned about you (such as what cusine you prefer) when searching for a nearby restaurant.
Microsoft Research has a interesting article called Exploring New Frontiers of Search that describes concept based search using WS-LDA (Weakly Supervised Latent Dirichlet Allocation) and context aware search using Variable-length Hidden Markov Model (VLHMM) . They're both data mining technigues.