One of my client has got a domain with 2 extension .net and .com .com domain has pr0 where .net domain has pr5 (which not use at all) the content is same but hosted twice, My client is using .com with pr0 what I have to do to exploit pr5 of .net Tow domains are same but with different extension. The content is same but hosted twice. thanks for your comments
I would do something quick as if they have identical content you will get done for a dupe content penalty. I just did a permanent redirect from one site to another and (higher PR in the page pointing to the other) and it is going perfectly. Make sure all pages are the same though (same extension as well ) htm to htm etc. You should be fine.
Maybe the site that has PR5 has many quality links than other site that has PR0. Try to get more quality links for your PR0 site.
Instead of getting penalty for content duplication 301 Permanent redirection is best option to transfer your old domain page rank to new domain page rank alongwith all the back links achieved for old domain.