301 redirects

[StuUK]

Does wordpress have some sort of built in 301 redirect thingy? Ive moved my site around and swapped an old one for a new wp version. When I type in sau "mysite.com/main/aboutus" its automatically redirecting to "mysite.com/aboutus" which is correct.

Also I have a few page links showing in google that say mysite.com/?p=59. This was before I change the permaliks. I have manually create 301 redirects in the htaccess file, but for some reason these dont redirect, while others such as mysote.com/products do fine. Would the ?p=59 be causing some bizarre problem?

And finally what do you think of Permalink Redirect WordPress Plugin? any good?