Microsoft has applied for a patent on metered "pay as you go" computing, a concept under which users would get subsidized or even free computers and then pay based on both the software they run and the computing horsepower they actually use. The company filed the application back in June 2007 but it has only recently been made publicly available online.

The application highlights what Microsoft sees as the future of computing from a consumer's standpoint, noting that the end user could end up paying more for the computer under this scheme, compared with the one-off cost entailed in the existing PC business model, but would benefit from the deferred payments and by having a system with an extended "useful life."

Fees would be lower for low-performance chores, such as writing e-mail or surfing the Internet, and higher for more demanding tasks such as gaming. I frankly don't see this model coming to reality anytime soon but it's an interesting concept nonetheless. Pricing will be the biggest challenge to Microsoft's plan.