Search firms Yahoo, Google and Microsoft have focused on the cell phone so far. You can try their efforts at http://m.yahoo.com/, google.com/m, and Windows live search.
Text entry is difficult on a cell phone keyboard, so Google and Microsoft are working with voice-based search. You can try them at 800-GOOG411 and 800-555-TELL.
Others are also experimenting with larger form factors than a touch screen phone. One example is Intel's Mobile Internet Device. Its features include a four or six inch touch-screen display, stripped-down version of Linux, fast restart from suspended mode, retractable keyboard, GPS radio, and a camera.