Venture capital is back; 2011 was a banner year for venture capital investments in wireless. After the recession of the past few years, venture capitalists came out in force during 2011 to invest a total of $6.3 billion in mobile-focused companies, according to Rutberg & Co. That's just slightly less than the high of $6.4 billion that VC firms delivered to mobile in 2006, the biggest year of VC investments in mobile in the past decade. According to Rutberg, mobile applications comprised $1.8 billion of the $6.3 billion total in 2011, with infrastructure contributing $2.6 billion, devices scooping up $1 billion, carriers netting $500 million and semiconductors nabbing $400 million. Which VC firms made the most investments? Find out in our special report.