28% of American adults use mobile or social location-based services, including mobile maps

"More than a quarter (28%) of all American adults use mobile or social location-based services of some kind. This includes anyone who takes part in one or more of the following activities:
28% of cell owners use phones to get directions or recommendations based on their current location—that works out to 23% of all adults.
A much smaller number (5% of cell owners, equaling 4% of all adults) use their phones to check in to locations using geosocial services such as Foursquare or Gowalla. Smartphone owners are especially likely to use these services on their phones.
9% of internet users set up social media services such as Facebook, Twitter, or LinkedIn so that their location is automatically included in their posts on those services. That works out to 7% of all adults."
Source:  Pew Internet & American Life Project, 6th September 2011

Google own 3 of the 5 most-accessed mobile apps in the UK

"In April 2011, 40 per cent of the 21.8 million UK mobile internet users accessed a connected application*. Google Maps ranked as the top mobile app with 6.4 million users, reaching 73.3 per cent of all UK app users. Yahoo’s Weather app ranked second with 3.6 million followed by Facebook’s app with 3.5 million unique visitors. Another two apps published by Google - Google Mobile and YouTube - rounded out the top five, highlighting Google’s strong position among UK mobile consumers."
Source:  Data from the GSMA Mobile Media Metrics Report, reported in a press release from comScore, 22nd June 2011

40% of Google Maps usage is through mobile devices

"Mayer revealed that 40% of Google Maps usage is mobile. And Christmas and New Years day had mobile usage of Maps surpass the desktop — which is a first for Google products. Google Maps now has 150 million mobile users. To put that in context, Maps for mobile had 100 million users in August of last year."
Source:  Marissa Mayer of Google, speaking at SXSW, reported by Techcrunch, 11th March 2011