I think you will find that godaddy's redirect service does not actually alias your site in a manner that will be helpful in the search engines.
I believe they use a 100% frameset so it looks like the site is Other-Site-Example.com, when it really is www.example.com/directory/ - however the search engines will not recognize these domains as the actual site, and also no one will be able to deep link to content sections.
Godaddy, among other hosting companies, has pretty inexpensive hosting - I think it starts at $4 per month.
You should really considering just hosting each site separately - or not using the other domain names and just making a "mega" site.
Thanks,
Oriana
(I pasted their instructions here in case I didn't explain it well):
Park/Point additional domain names.
If you already have websites somplace else that you
are moving to ThirdSphere Hosting.
STEP 1)
Setup a subdomain
Click here to learn how to set up a new subdomain.
Create the sub-domain via your control panel. Click on the sub-domain link in your control panel to get started. Once you are there, enter in the
sub-domain of your choice in the text box and click on the "add" button.
For instance if you have a domain name called [Cookies.com...]
and you wanted to create another website called [Milk.com...]
you would create a subdomain called "milk" Sometimes people
put in Milk.com but that convention would not work. It must be "milk"
This process has now created a sub-domain on your account. This has also created a new sub-directory in your public_html directory. This sub-directory will be named exactly what you have chosen for your sub-domain name.
Now you must upload all the files you would like to use for your sub-domain website to this directory. There is also a cgi-bin directory automatically created for you in this directory. You should upload your sub-domain website scripts to this cgi-bin.
Then you should check out your subdomain to make sure all the files got uploaded properly and you can do that by going to a link like:
e.g., [subdomain.domain.com...] or [milk.cookies.com...]
Once you are comfortable that that site is working perfectly then its time to do the next step..
STEP 2)
If you have an existing domain name, you will need to point the DNS at us with your registrar or register a new domain name and point the DNS at us (if you have a hard time with this, email us with your username and password to your registrar account and will attempt to do it for you):
NS1.THIRDSPHEREHOSTING.COM 208.179.45.58
NS2.THIRDSPHEREHOSTING.COM 208.179.45.59
Please note: no matter if your domain name is new or you have just pointed the DNS to us from your current registrar, it takes up to 72 hours for your domain to propagate to all the major DNS servers around the world.
STEP 3)
Login to your web control panel and on the "Web hosting options" click the "Park/Point additional domains" link. You'll be taken to a new screen that has a web form just like this one:
You must fill the following fields using this information:
a) Enter the domain name you wish to park to your account.
b) From this drop-down box, select the subdomain you created.
Make sure both checkboxes are checked (as shown above)
c) Click this button to park/point the new domain name on your account.
Once you click this button, your credit card will be billed with a one-time $10 charge for the process of pointing your additional domain name.
When that is successful you will receive a message on the screen giving the status. If you domain is already pointing to us and has propogated (see note in STEP 2). Then in under 10 min (my experience is it happen in under 1 min), you can go to your new domain name and see exactly what you saw at your subdomain.
e.g., [milk.com...] or [milk.com...] should look exactly like [milk.cookies.com...] - because they are the same site. The part that we are most proud of is that all this is under your control, you don't need us for any of it.