bulk changing / adding tags to existing nodes

dear drupal experts.

i have a few sites that are up and running for sometime now.

i recently had a brainstorm (very late, it seems - lol) to re-organise the content (nodes) on my site into appropriate tags. i have created vocabularies and tags for various content types.

however, hundreds (thousands on some sites) of existing content are not tagged as such.

how can i go about bulk tagging (sometimes changing / updating the tags) these existing content efficiently (ie, without having to tag them one by one)? i did some searchs on changing node tags, but cannot find answers to the question i am asking.

any help / guidance / module would be greatly appreciated.

thanks in advance.

fazz

http://greenlane.bukitjelutong.net/
http://club.my-kart.org/
http://www.thefazz.com/me/