http://blog-tools.googlecode.com/files/merge_tags.py
(need python to run it)
You will have to create a file with the lists of tags to process. Each line (consisting of coma separated tags) in that file corresponds to a group of tags to merge (with the first one being the one to merge into). For example, if you want to merge all the foo into bar, the file will look like this:
bar,foo
To get the list of options, run the script with -h.
HTH
