I don't mean to sound too much like Karl Marx here, but it seems that one increasingly popular way to reduce energy consumption and promote renewables is to eliminate, or at least selectively reduce, property ownership.

Communities and companies aren't banding together to lounge around in yurts and loll on blankets like the smelly commune dwellers in Easy Rider. Instead, business models have emerged that effectively cut costs and offer peace of mind by taking the title to real and personal property off the hands of homeowners and businesses.

Some examples:

--Cloud computing and software-as-a-service companies effectively allow large and small businesses to outsource their applications and data centers to third parties like IBM and Google. You get all the benefits of computing without the headache of virus updates, replacement cycles and upgrade contracts.

--Virtualization, in turn, makes cloud computing and software-as-a-service more efficient. Virtualization doesn't take software out of your hands. Instead, it reduces the footprint of the computing resources required by your third-party service provider. In the end, virtualization leads to less hardware sold.

--Car share pioneer ZipCar is planning an IPO. Added bonus: consumers only pay a fractional, indirect, portion of insurance and taxes. City CarShare has launched what may (or may not) be a workable alternative to ZipCar. Instead of a central company owning the cars, individuals put their cars in a rideshare pool and earn money when others use (and trash) their cars.

--Cisco, IBM, demographers and various futurists predict that there will be a massive influx from rural and suburban communities to urban cores. This will reduce travel, but will also likely lead to a swapping out of lawns for public open spaces. Check out this proposed skyscraper in China with public gardens rising into the sky.

--Companies like Metrus Energy, Ice Energy and Skyline Innovations are offering to retrofit commercial buildings. These companies keep title to the bulbs, heaters and air conditioners installed in a building and then charge residents a fee for light, heat and cold air. (Ice Energy only works with air conditioners.) Ideally, the fee is less than the amount you would have paid to run your old, inefficient appliances, and it includes maintenance. Either way, suddenly you have a building where you don't have the burden of owning the machinery inside of it.

Recurve, Austin Energy and others have toyed with the idea of giving stuff -- new insulation, LED bulbs etc. -- to homeowners to curb peak power. Under this scenario, you own the property but don't pay for it and agree to use it. Call it property ownership lite.

--SolarCity, SunRun, Sungevity and SunEdison have succeeded in convincing residential and commercial customers to install solar panels under lease programs that pretty much function like service contracts. Title only passes to the building owner, if at all, after a period of years. Some solar and wind developers have also told me that they have cut deals with landowners in which the developer pays for the lease on the land for the solar panels by sharing the revenue with the fee holder. In reality, this eases the developer's burden of carrying any interests (namely, a lease on a separate payment schedule) in real estate.

--District heating, which involves building a network of pipes to deliver heat to a community, continues to grow in select areas. In Finland and a few Nordic cities, heat from data centers (cf. the first item discussed in the linked piece) will be piped into homes. In Hawaii, a district cooling system is being planned. Again, this is heating and cooling without having to own heaters or air conditioners.

--Nissan and others are tinkering with the idea of letting car owners lease or temporarily own the batteries in their electric cars. After a few years, the batteries then get transferred to utilities for local power storage. The system would give an electric car a longer, zippier life and it would free the consumer from the risks inherent in owning batteries.

Meanwhile, Better Place continues to tout its system in which consumers don't own the batteries in their car and can swap them at will. It will launch first in Israel, where many drivers don't own their car: their employers give them the use of cars as a fringe benefit.

Note in these examples that these companies aren't reducing ownership because of some sort of inherently evil political agenda. Nor does anyone want to punish capitalism -- to the contrary, everyone here wants to make money. Instead, these business plans revolve around better utilization of resources, reducing capital and up-front costs, and paving the way for new, experimental technology.

The risks are also calculated. Boxer-shorts-as-a-service likely won't be Salesforce.com's next foray. And some sharing systems need work. In 2008, I visited Copenhagen for five days and each day wanted to ride one of the oft-touted free bikes. I could never find one. Most of the bikes had apparently been clipped. But for-profit rental services abounded.

Not everyone likes the idea of outsiders telling them what to do with their aging, dilapidated appliances and material goods. Earlier this year, an attendee at a panel discussion on home energy consumption told me he tried to convince his father to replace his old fridge with a new, energy-efficient one. The new fridge would, with PG&E rebates, pay for itself in lower bills. Dad's reply? You can have this fridge when you pry it out of my cold, dead hands. But imagine that it's 1940 for second. People weren't insisting the White House continue Weisswurst imports.

Again, we aren't rushing headlong into a world where we all live as one and never argue over who gets to sit in the La-Z-Boy. But the kindergarten mantra -- if you can't share, it's going to go away -- seems to be creeping up in popularity.