Usability 
Online mobile guides to major US cities plus London and Paris from the publisher of the Insider's Guide series of travel books.
Guides list recommended Shops, Attractions, Tours, Transportation, Museums, Galleries, Neighborhoods, Spas, Salons, Theaters and Night Spots with descriptions, price range, address and click to call phone numbers. Page sizes can be rather large, up to 60 KB, which may be a problem for some mobile browsers.
There's also an iPhone version of the site at wheretraveler.com/mobile which offers some additional feature including a currency converter, tip calculator, language translator, airport delay lookup and lists of airline and car rental phone numbers. Source: Oh! Mobile Directory