Microsoft announced a cross-licensing agreement with Amazon.com, opening at least a portion of their respective patent portfolios to each other, on Feb. 22.

"We are pleased to have entered into this patent license agreement with Amazon.com," Horacio Gutierrez, Microsoft's corporate vice president and deputy general counsel for IP (intellectual property) and licensing, said in a statement. "Microsoft's patent portfolio is the largest and strongest in the software industry, and this agreement demonstrates our mutual respect for intellectual property as well as our ability to reach pragmatic solutions to IP issues regardless of whether proprietary or open-source software is involved."

Details of the agreement, and the actual amount of money changing hands, were undisclosed by Microsoft. According to TechCrunch, Amazon.com isn't commenting beyond what Microsoft has said, but reports indicate that the online retailer will be the one putting up the cash for the deal.

As my colleague Darryl Taft points out in his most excellent article on eWEEK, Microsoft has signed more than 600 licensing agreements since launching its IP licensing program in 2003, with companies ranging from Apple and Hewlett-Packard to Nikon and Fuji Xerox. Such deals help avoid those pesky patent-infringement lawsuits hated by virtually everybody except IP attorneys with Bentley payments.

But we can conjecture freely about the possible ramifications of a possible IP licensing deal between Amazon.com and Microsoft. Both companies, obviously, have been deep-diving into everything tablet PC-related of late; Amazon.com recently announced an SDK (software development kit) for the Kindle that will allow developers to create applications for its high-resolution e-ink display, and Microsoft along with its hardware partners has been planning a major foray into the tablet space.

A cross-pollination of ideas between the two companies, of course, would allow them both to compete more heartily against the upcoming Apple iPad, which potentially threatens a wide variety of segments.

Microsoft already has a "Kindle for PC" app that ports Amazon.com's e-reader interface onto a desktop or laptop, but I could see Amazon.com benefiting from Microsoft's explorations into tablet PC software; Amazon.com CEO Jeff Bezos has suggested in the past that his company is exploring color screens, but that any such development is "multiple years away." If that's true and not just a competitive bluff, then Microsoft's patents could help speed that R&D rate; Amazon.com could also potentially take advantage of Microsoft patents like this one, which allow devices to be wirelessly charged.

Either that, or else Amazon.com could utilize some of Microsoft's rumored Courier technology. Until something concrete comes out, though, it's all smoke and mirrors.