Microsoft co-founder Paul Allen recently released a book titled: Idea Man: A Memoir by the Cofounder of Microsoft in which he gives vent to his umbrage against Bill Gates in a candid manner.

Having been overshadowed by Bill Gates, the book seems to be an attempt to salvage the lost limelight by the author. CNET reported that Allen wrote in the book: I was the idea man, the one who'd conceive of things out of whole cloth. Bill listened and challenged me, then homed in on my best ideas to help make them a reality.

While the book reveals the details of his tumultuous relationship with Bill Gates and Steve Ballmer, none can question that Paul Allen made a fortune despite leaving Microsoft in 1983. According to Forbes, Paul Allen has a net worth of $13.5 billion as of 2010.

He left Microsoft in 1983 after being diagnosed with Hodgkin's lymphoma. Since then, Microsoft share prices have rocketed and Allen's net worth as well. Forbes listed Allen as the 37th richest man in world in 2010.

Unlike Bill Gates who has been on a charity spree, Allen has gone ahead and fulfilled some of his wildest dreams. What does a man with $14 billion and an interest in sports, space, Jimi Hendrix and explorer Jacques Cousteau do? Allen justified his interest by making key acquisitions in his area of interest.

Allen owns the football team Seattle Seahawks and basketball team Portland Trailblazers. Allen also owns a 416-foot yacht called Octopus, built a space ship, SpaceShipOne, is the primary financer of the $240 million high-tech, interactive music museum EMP in downtown Seattle and also has a collection of vintage planes currently exhibited at Paine Field Evertt, Washignton.

Here is a slideshow which showcases Paul Allen's indulgence: