I found it interesting to learn about the impetus behind AirBnB while at a Inman conference in San Francisco. The idea was launched by several guys who literally wanted to see if there was a market for renting an air mattress to area visitors. Well, there was and the site took off from there. Now AirBnB has vacation rentals around the world. Similarly, even a cursory review of Craigslist vacation rentals will reveal hundreds of lodging options from a lowly couch to luxurious condominiums with all the benefits of home away from home.
I must offer a few words of caution to those considering one of these two alternatives. First, know what you are getting. Ask if the party you are renting from is reputable. Are you turning your money over to a stranger? What protections do you have? What would you do if you arrive and the property is not available, is not as described, or worse , the whole thing is a scam. Craigslist is replete with those offering multiple ways to help you part with your money. Is the property safe, secure, etc...
In Chicago, as of 2011, vacation rentals must be licensed. Ask for that information before you do business with any rental property owner. And, that goes for AirBnB rentals as well. Just because they are listed on that site doesn't mean they are licensed. MANY MANY MANY rental operators are not licensed and by doing business with them you are at risk.
A better alternative is to consider one of Chicago's many Bed & Breakfast options. Chicago licenses all B&Bs and to get this license, the establishment has to undergo a thorough inspection by the buildings depatment and the Chicago Fire Department. Each year the properties are re-inspected. Additionally, reputable B&Bs are members of the Chicago Bed & Breakfast Assciation http://www.chicago-bed-breakfast.com. Check with that group to find links to all Chicago B&Bs.
Chicago has many alternatives to the traditional hotel, but exercise caution in making your choices. Always ask if the benefit of saving a few dollars is woth the risk of a ruined vacation or visit.