Registerfly and enom offer free forwarding if your domains are there. some others do as well. Third party services are out there as well such as
http://www.domainredirect.com , but you usually have to manage them individually with separate logins per name making it difficult.
Parking is the way to go though. I have a reseller hosting account where I park almost as many names as you have on a few main domains. Many are parked at the domain in my sig and if you type in any of those names individually, they lead directly to the for sale page for that name. I also get stats for referrals when names are typed in, letting me know which get natural type-in traffic. The name also stays in the browser address bar without hidden frames. See how this works:
http://www.adoptabledomains.com - main domain
http://www.fish.us - parked on the above
-RJ-'s script does the work of taking it to the sale page after arrival, but http redirects or other scripts can be done from standard web pages or you can just send all to the same domain index page.
If you are interested, I could set up a name on my hosting account for you, setting your own main domain as a default nameserver and giving you full DNS control. Pricing would depend on what kind of bandwidth your domains use and if all domains comply with my TOS contract.