I've recently started favouring Git instead of SVN for my newer projects and one of the things I do religiously is tagging.
Tagging in Git is very easy and simple, but I ran into a small problem. I created a tag and named it incorrectly and pushed it to my remote repo before I noticed the mistake. So I deleted the tag and created a new one with the correct name and pushed it. Then I did a pull to ensure I was completely synced with the remote repo and it pulled down my old tag that I just deleted...
It turns out that in order to delete a remote tag you need to do the following (replace 'MyTag' with the name you gave your tag):
git tag -d MyTag git push origin :refs/tags/MyTag