Ankh-Morpork Temple of Om
There is a temple to Om located on the Street of Small Gods in Ankh-Morpork. It is first mentioned in The Truth when it is visited by Mr. Pin & Mr. Tulip who need to raid it for robes to disguise themselves. Mr Pin very nearly strikes the elderly priest on the head with a silver candlestick, but is stopped by Mr Tulip who recognizes the candlestick as a very valuable antique, and employs his fist instead.
The Temple is later used in Going Postal by Moist von Lipwig when he places prayers to the gods asking for a very large sum of money, visiting the temples of Om, Blind Io, Offler & Anoia (less of a temple, more of an office over the bookie's on Cable Street). After this miracle comes to pass the high priests of all four religions come to see the Patrician, demanding that Moist's discovery of a huge sum of buried money be acknowledged as a gift from their god, and to demand a tithe.