If you find yourself writing a lot of opening and closing tags by hand you really should check out Zen Coding:

Zen Coding is an editor plugin for high-speed HTML, XML, XSL (or any other structured code format) coding and editing. The core of this plugin is a powerful abbreviation engine which allows you to expand expressions–similar to CSS selectors–into HTML code.

A very large variety of text editors are supported by the plug-in, with alternative implementations for editors like Emacs and Vim.