Shortly after moving into a new building at a previous job, the boss told us we'd all have to watch our language. There was a chance some of the company higher-ups might walk by, and he didn't want them to overhear any of us swearing. One co-worker came up with some creative censorship, exclaiming one night, to everyone's surprise, "Mother of penguin!"
"Mother of penguin?" another co-worker asked.
I still think that's one of the more clever, amusing euphemisms I've heard.
