Menlo Park, California -- Big Brother is here. And he's selling parking spots.

Sensors and the applications that can run on them were the main focus of startups at SmartCamp, a global business plan contest sponsored by IBM. Ten years ago, companies like Dust Networks and Intel were showing off prototype applications for the "extroverted computing" market, a term I made up in 2003 that failed to catch on. SynapSense and others brought sensors to the data center a few years ago while APS today said today that it planned on inserting sensors into its grid for monitoring and self-healing applications. Now, other applications are coming to market.

StreetLine, for instance, showed off a system that effectively allows consumers to find and reserve parking spots while they drive. The company embeds mesh sensors (which include technology from Dust) into parking spots that communicate with drivers. Drivers can also put more money into the meter remotely via a cell phone. Streetline, along with medical IT company CareCloud, shared the grand prize. The two now go to the international finals in SmartCamp later this year.

Ideally, information on available spots will free up the streets.

"Thirty percent to 35 percent of the traffic in a city is caused by people looking for parking," said CEO Zia Yusuf.

The city benefits, too. Only around six percent of expired meter violations are ever ticketed or collected. With StreetLine, enforcement officers know at any given moment exactly which cars have run out of time. The system can also tell cash collectors which meters have the most coins in them. Trial cities have seen an increase in enforcement levels.

San Francisco has installed 3,500 meters and wants to impose dynamic pricing, i.e., letting consumers outbid each other for prime spots. Rigging up a parking spot, including the amortized price of the software and repeaters, comes to around $250. European startup World Sensing has a similar application, but is not as far along in the development process.

"The payback can be in months," he said, describing parking spots as "a 20-foot-by-five-foot, increasingly valuable piece of real estate."

In a slightly different use of sensors, iFind showed off a tagging system called Wandering Shepherd for cattle and other livestock that monitors the animals' body temperature via satellite. If a cow or group of cows suddenly experiences a temperature spike, that can be an early sign of an outbreak of hoof-and-mouth disease or Mad Cow Disease. Those cows can then be quarantined. Airborne diseases among cattle can travel 50 miles in a single day.

"Within ten days, [the epidemic] can be across 25 states," said CEO Neil Helfrich.

Two Canadian ranches will start field trials in the first quarter of next year. The USDA is looking at sensors to track six kinds of livestock.

The technology can also track movement, so if a cow starts traveling at 60 miles an hour, it could be another case of rustling.

Next, iFind wants to develop an application that can trace meat from the hoof to the package. (Brazil is working on a similar technology.)

Then there was AquaCue, which developed a sensor and software package that reads water meters and delivers the information to a distant computer or cell phone. Now, utilities send out a reader every other month to check your meter.

The system costs $400 and many consumers pay only $1 a day for water. So how do you make it worthwhile? Leaks -- a single leak can cost $3,500.

"32 percent of all home insurance claims are leaks," said Shahram Javey, CEO. Hence, your insurer may pay for the system. When Javey was testing his prototype in his own home, he discovered a leak.

AquaCue has also created a behavioral application that gives consumers a smiley-face-or-frown sort of grade to improve their rate of water consumption. In early trials, water consumption was reduced as much as 11 to 26 percent.

Other companies: CitySourced has a cell phone app that let people report potholes and other issues to city agencies.

Tags: disease control, dust networks, energy efficiency, green it, ibm, parking, sensors, traffic, water meters