Useful links:
Mobile Marketer - The news leader in mobile marketing, media and commerce
www.mobilemarketer.com
Very good source of useful information from around the world regarding mobile marketing and mobile commerce. If you want to keep in touch with the latest developments, this is the place to visit.
Marketing Charts
www.marketingcharts.com
Source of marketing research charts from various industries. Data about smartphone market growth, the use of mobile content and more can be found here frequently.
ReadWriteWeb
www.readwriteweb.com
Popular technology blog. Source of insightful information about mobile, internet and more.
Canalys
www.canalys.com
Provider of technology market data and analysis. You will find their market data being quoted frequently by various other websites and blogs.