WhatsOpen.com offers a Web application that shows users nearby stores and operating hours. That's the sort of thing that a mobile advertising strategy can build off of. It also suggests something else about the nature of mobile Web services optimized for handhelds.
To wit, given the greater difficulty of interacting with the device, compared to a PC, maybe large portions of the experience need to be more like linear TV, as heretical as that may seem. Push useful data to me. Not all the time because that kills battery performance. But sense when it is likely I am looking at the screen. Show me something interesting.
Combine Real Simple Syndication with streaming. Maybe not streaming video, maybe streaming text. Adjust the feed based on my location. People talk about the difference between a lean-back experience and a lean-forward experience. Maybe we need to work on a stand-up experience: screen-based information and entertainment adapted for a user that is standing up and moving.