Change template dynamically

Just in case someone comes here to copy pasta without looking at the codex.

THE APPROPRIATE FILTER IS »template_include«

See: Codex – Filter Reference

As Radek pointed out that method can destroy your theme.

Additional information: The article »Don’t use template_redirect to load an alternative template file« by Mark Jaquith, where he says, in a nutshell, template_redirect is for redirects, template_include is for includes.