We've blogged about Intellectual Ventures before, as a company to monitor when researching IP values and licensing. John Amster was IV's VP of licensing prior to his founding of RPX in 2008; RPX identifies key tech trends, buys key patents that are critical in tech industries, and licenses them to tech companies. (It's kind of a positive spin on the patent troll model ... RPX helps tech companies build defensible positions. (Of course, if a company refuses to participate, there would undoubtedly be Damoclean, patent-troll-like litigation hanging over its commercial head.)
These guys must be smart. According to their Web site, their client list is growing exponentially (over 70). Now, they have informed the SEC of their intent to raise up to $100M in an IPO, managed by Goldman Sachs and Barclays Capital.