I also wish to have the option of having different Meta Tags for each page or post on my blog. I have uploaded the plugin and found that the following two fields maybe meant for customization.
"Additional Post Headers" and "Additional Page Headers"
"What you enter here will be copied verbatim to your header on post pageS. You can enter whatever additional headers you want here, even references to stylesheets."
It seems to say that the header information entered here will be reflected in ALL POSTS or ALL PAGES.
I am not clear how this Plugin can add different descriptions and keywords for each page or post individually.