The website that I'm working on is looking for an ad server. Preferably one
that is free and open source such as:

http://www.openx.org/

Any recommendation on an ad server that is fairly easy to get up and running.

If not open-source a fairly inexpensive one that would be installed on our
server would work also.

Many Thanks!

John V.

OpenX is an easy one to setup. I am using it on my sites. If you want something
else then there is DMX (http://direct.rightmedia.com), it s you manage your
ad as well as have several advertisers compete against one another for your
site ad inventory. I use OpenX as well as DMX and I am happy with it.