This doesn't work on wordpress.com sites but the only thing that shows is the BTC address and text message,the php widget does not show.Just for those who use wordpress.com blogs.Seems that wordpress.com doesn't allow anything other than basic html on their site.
Yeah I was afraid of that.
Wordpress.com does block all scripting, to the point where you can't even embed video using standard embed code. They will allow Youtube shortcode embeds, but that's about it. The lack of script embedding on Wordpress.com is why I dumped that host for my own standalone in the first place.