Transmeta, the company behind numerous popular low-power PC products, has filed a fairly broad lawsuit against Intel. Citing copyright infringement as the reason, Transmeta claims that Intel is violating numerous patents in production of many of their CPUs, going back quite a ways, encompassing the Pentium III, Pentium 4, Pentium M, Core and Core 2 series. They say they have already have sought compensation from Intel, and that it didn't go so well:

"Intel has acknowledged that Transmeta has been an innovative spur to some of Intel's own development efforts, roadmap decisions and new product successes,'' he said. ''At the same time, Intel has practiced multiple Transmeta inventions in its major microprocessor product lines. After endeavoring to negotiate with Intel for fair compensation for the continued use of our intellectual property, we have concluded that we must turn to the judicial system to be fairly compensated for our inventions."
No specifics as to what patents are violated are included, nor does it reveal the amount of money they are after. I definitely want to see what, exactly, Intel supposedly violated. Most likely it would have something to do with power consumption or on-chip security, since those are the two key areas Transmeta specializes in.