Dwayne,
See the second link in my sig. It's a place where you can put your unused domains and you keep all the ad revenue.
Basically, how it works is, you pay them @$100 and park up to 100 domains. You choose the keywords and it builds a little site for you with adsense on it. Then, you use whatever methods you normally do to drive traffic. The little sites are kind of SE friendly... not the best SEO in the world but not bad.
Anyway, it works out to @9 cents a year, per domain. You can make more than 9 cents a year off each domain with AS, can't you? If you want to place more than 100 domains, you can buy additional credits. I just started using them so I don't know yet if the $100 is per year or forever. Either way, it's a decent deal.
My opinion is, if you have quite a few unused domains, it's a good idea to earn a little cash and retain control over how you do it. If you place your domains with a parking outfit, you don't have any control over what the keywords are and they take a cut of the ad revenue. You can still drive traffic but not much else.
With this outfit, you retain control and get all the revenue. Granted, it's not free and, if you only have a few domains, not worth the investment. But, if you buy domains in bulk, you can put them in here and take them out at will, while having the opportunity to earn a few bucks along the way.
I buy about 10 domains at a time but can't build 10 sites all at once. So, I put the idle ones here until I'm ready for them. Usually, before I use up those 10, I've bought 10 more so, my stable of unused domains keeps growing.
One advantage is, you can get some SE listings while you're building your sites. Instant SE listings when your real site goes live!
Or, if you have a desireable URL and don't have the time or ambition to build out an entire site, put it here and grab type-in traffic. Type-in traffic is how a lot of the professional parkers get their traffic anyway. Not a lot of cash in an archane domain unless you have a way to drive traffic, if it's not a type-in kinda name.
Oh yeah... the affiliate link in my sig isn't cloaked so I trust you guys not to screw me. Karma matters.