And me Text Filter Suite plugin is still aroun' t' add piratey goodness t' yer WordPress site!
Install th' plugin and activate th' ‘TFS Core’ and ‘TFS Pirate’ plugins, with a chest full of booty. It will automatically turn th' content on yer site t' pirate-speak on Talk Like A Pirate Day (September 19 each year). On other days, it will leave yer content alone.
If ye have a particular post that ye want t' always be in pirate speak, just add a custom field named ‘post_filter’ (and/or ‘comment_filter’ t' filter th' comments) with a value o' ‘pirate’.
Aye, this is probably more complex than it has t' be. But I wrote th' original plugin a long time ago. Aye, I need t' rewrite th' thin' from scratch, give it a settin's page, etc. I’ll do that in me Copious Free Time.