Change Post Title Structure

Hi,

At the moment, my post title structure is:

%blog_title% > Blog Archive > %post_title%

How can I set it so that it becomes just:

%post_title% | %blog_title%?

Main reason why I want to change this is because when me or someone else uses the Tweetmeme plugin the Tweet becomes filled up with the blog title before it’s able to show the post title and by then it’s already close up to 140 characters.

I have tried SEO packs and they seem to work nicely however it doesn’t affect Tweetmeme’s link structure.

What can I do to fix the title structure in the Twitter plugin? Change the blog title itself or edit the plugin?

Thanks