A quick post to keep you entertained while I'm on my break, the Flickr group Scymraeg has had this truly beautiful sign uploaded recently.
The English is clear enough, and the Welsh is grammatically perfect. I assume that whoever was in charge of creating the sign e-mailed their usual translator asking him what "No entry for heavy goods vehicles. Residential sites only" was in Welsh. He must have received a very swift response and immediately ordered the sign and had it put up.
Unfortunately the reply he received wasn't quite what he expected. The Welsh part of the sign says:
I am currently out of the office. Send any work to be translated.