I get bored opening and closing tags when writing html - so I hacked-up a tagging service.
http://www.monkeyfood.com/software/TaggingService/
It tags the selected text - the type of tag is determined by a prefix ":"
e.g. if you selected the following text:
p:This is a paragraph
and invoked the service then you get it replaced by:
<p>This is a paragraph</p>
It has a Keyboard shortcut of Command-Shift-\