OK, here are a few sites to look at:
http://www.arenting.com/
http://www.UNDERTROUSERS.NET/
http://www.XN--4DB4BK.COM/
http://www.xn--4dbacpcqfb4dm0f3a.com/
These sites were getting about zero traffic, and zero income when parked, now they're getting a little traffic, with little income as well. The last time I checked they all got indexed by Google, which wasn't the case when they were parked. The time setting them up was minimal. recently Google adsense started "punishing" some of the sites for lack of original content, so I changed to Adbrite, which is also making some minimal amount. WhyPark recently set up there own ad network, which is still in Beta, and they are paying presently 100% income for all the testers. In any case, I am making a considerable bit more with them, then I am with Google and Adbrite.
My suggestion to you and others is quite simple. If you have domains with none or close to no traffic, or traffic which is not converting, or a new domain registered or purchased for building a web-site you gain;
1. Indexing,
2. Generally minimal income, which may at least cover domain renewal fees.
I have not yet experimented with traffic domains, with low CTR or PPC to see if the income improves, but this is definitely coming. I have a few domains right now at multiple-parking companies, experimenting with them, so I will definitely be doing this with WhyPark as well.
Another couple of advantages is ability to add very simple new content pages, and links, which can either be sold, or linking to your own sites.
All in all, for it's cost, which includes free hosting. I think those options are worth while.
Good luck.