People who are considering renting out their homes should confirm that they're not violating city laws or terms in a lease or homeowners' association, or avoiding a hotel tax, says Janelle Orsi, executive director of the Sustainable Economy Law Center in Oakland, Calif.
"You usually can't operate a hotel out of your house," Orsi says.
Bikes. Like many parts of the sharing economy, bike sharing works best in large, metropolitan areas. The general concepts underlying bike-sharing services such as City Bike in New York City and Hub Way in Boston originate in Europe.
"Population density plays a part in this, and populations in Europe are more dense," says Jon Lal, founder of BeFrugal.com and a regular user of Boston's bike-sharing program.
Bikes can be rented for one-way trips. Lal, who lives in a Boston suburb, says he pays an annual membership fee of $85 and an hourly fee of $2. The service also has 24-hour passes for $6 and 72-hour passes for $12. Hourly rates vary depending on whether you purchase an annual membership or one of the expiring passes.
Before using a bike-sharing service you should consider bringing your own helmet, how comfortable you are riding a bike in city traffic, being sweaty upon arrival and how close your destination is to the program's bike racks.
Dog sitting. For a $39 fee, Sam Mojtabai rents his home in Thousand Oaks, Calif., to two to three dogs a night through DogVacay.com. The company takes a 15 percent cut and provides marketing, insurance and booking services.
As an insurance company consultant who works from home – and with plenty of land for the dogs to roam – Mojtabai says it's a great gig to make an average of $600 each month. He loves dogs, but says the job isn't for everyone.
"You have to be an animal lover and you have to be patient with them," he says.
Prices at the dog-sitting services, which include Rover.com, are set by the hosts and are usually cheaper than a kennel. DogVacay says its rates average half of what local kennels offer, with more than 10,000 hosts booking hundreds of thousands of "doggy nights" annually.
[Read: Create Better Money Habits in 2014.]
Wi-Fi. In shared spaces like airports and conferences, sharing Wi-Fi can be easy. But since you're not always lucky enough to find an open, secure network, exploring other options is a good idea.
Yourkarma.com sells 1GB of data for $14 and lets users earn 100MB of free data for every new user they share their Wi-Fi connection with. Data itself isn't shared, only the connection. Coverage areas are limited, so check with the company before signing up.
Another service, Fon, is popular in Europe and is slowly gaining a foothold in the United States. For $50 you get a Fon router for your home that other service members can use while you're away. The hotspots can be found on a Fon map.
With the sharing economy decentralizing who provides services, the best way for newcomers to test the sharing waters may be to try one service and see how it goes, says Krause of TradeYa. But even before taking that step, consumers should first verify the service provider at least via social media and communicate online with them, he says.
"The amount of fraud is very, very low," Krause says of the sharing economy. But rating systems, he says, should help keep the systems safe.
There's also the idea of going with your gut feeling. Seeing a pink-mustached car approaching to pick you up may be more comfortable if you check out the driver's ratings online first, but seeing trash on the car floor can be an obvious sign to tell them to continue driving without you.