"Pungen" is commonly used. "Tegnebogen" is also commonly used but it connotates to a larger and more specific thing than "Pungen". The meaning of "pung" just means any small bag in which to carry something and is also used about kangaroos. People aren't likely to think of a scrotum if you use it. "Tegnebog" specifically means a wallet, specifically designed to carry cash, plastic cards etc.