Consider your needs rather than whether you need a car. If you need to get to and from work check out something like this: http://www.erideshare.com/carpool.php?city=Cincinnati

If you need to use a car occasionally, you could try to organize something in Cincinnati with agencies like:
http://www.flexcar.com/
http://www.zipcar.com
http://www.carsharing.net/

Doesn't look like there is anything currently operating in Cincinatti.

Or sit down and do the math. It's often cheaper to rent a car or take a cab than buy, licence, insure, store and feed a car if you only need it occasionally.

Unless the info on this page is BS, Cincinnati looks like it as least heading to being more bike friendly
http://www.cincinnati-oh.gov/transeng/pages/-6807-/