I always struggle when it comes to post titles and titles in general, because I'm never sure which words to capitalize and which not. Your friendly next door nerd Brett Terpstra created not only a script but also an API that turns your title into the right TitleCase format used by AP and co.
To make the usage a bit easier, I wrote a short TextExpander snippet that turns any title into the right form for me.
#!/bin/sh raw_title="%filltext:name=title%" api_url="http://brettterpstra.com/titlecase/" response=`curl --silent --data-urlencode "title=$raw_title" $api_url` echo $response
You can also find it in my downloads section.