I have a page with a URL like
http://www.example.com/subcategory/therealthing.
This URL should stay like this but I need to create a shortcut that looks like
http://www.example.com/realthing
That shortcut should take the user to the site with the longer URL
A method that is SEO friendly would be perfect.
What's the easiest way if I don't want to change the permalink of the original site? I guess htaccess won't work for this?
Funny, I just answered something very similar to this. See the redirection plugin. Much easier than editing your .htaccess file yourself. Particularly if you need to do it a lot.
Take a look at the feature list for the redirection plugin. This allows you to setup redirects to other pages or do pass through redirections.