Good thoughts here, Interesting topic.
I wish we could get a 1-5 scale type poll in place so we can come up with more accurate data.
I use 1and1 for my main registrar and Godaddy as my secondary.
I leave my names at the registrar, forwarding right away to Sedo to watch the traffic for a few weeks. (is this an inaccurate gauge?)
If I see that it has decent traffic already, I'll try to forward it to another of my sites in a similar/same category.
If I don't have a matching category, but it gets decent traffic I'll "throw up"

a phoney-baloney site that's just a parking page where all the links go through to affiliates. (Example:
http://ibidubid.com ) I find for some names, I'll get anywhere from 10-50 bucks a month this way.
Also, sometimes I'll just forward the traffic with my affiliate link straight to the affiliate site, although I've heard this will piss off the parent affiliate if you burn up too much bandwidth. (as in the case of "worthless" popunder campaigns

) With this method, I am able to get a comission or two per month, i.e. the MP3 download clubs, posters, tshirts...
The way I see it, if your domain name is making more than $10/month parked, you should spend a couple of hours making a custom landing page with links through to affiliates. Why give it away? you just have to be patient. Instead of collecting dimes, you get a twenty every now and then.
Also, if the affiliate has lifetime comissions, you might just get repeat business, something that will never happen at a parking service.
good luck to all!
Andrew