301 redirects, domains and sitemap?

[Steveboy]

I have a number of domain names that sound similar to each other. I have one active site with the similar sounding domain names being 301 redirected.

I want the other domain names help my PR and search terms. Is it practice or a good idea to add the other domain names in the sitemap?

For example, my main site is example.com, however I own and redirect exampl.com. exampal.com and examples.com

Currently example.com has a PR of 5 when you search for "example". However when you search for exampl, exampal or examples, the main site "example.com" is no where to be seen.

How can I get example.com to appear when the other search terms are used? I thought owning the domain names would have helped.

Sorry if its a stupid question, Im pretty new to this game.
Thanks in advance guys

[edited by: caveman at 8:06 pm (utc) on June 22, 2008]
[edit reason] Exemplified. [/edit]

[SEOMike]

Start writing content and building links for the other spellings of the word. That's the best way to make your site relevant to a particular word.