How much do you tip when you get great service from a server at a restaurant? Twenty percent? More? Well, one Oregon couple apparently thought their waitress did such a great job that they allegedly tipped her with a tip she'll never forget; some methamphetamine.

According to the Daily Astorian newspaper, after downing their drinks at the Twisted Fish restaurant in Seaside, Ore., the couple left the envelope filled with meth.

When their waitress picked up the "tip," she became suspicious of the crystal-like substance and called police.

Police arrested Ryan Bensen, 40, and Erica Manley, 37, after allegedly finding more of the drug in Manley's purse and say even more was found when they searched their motel room. 

Bensen was arrested on charges of possession of methamphetamine and manufacture of methamphetamine.

Manley was arrested for possession of meth, manufacture and delivery of meth.

Meth is a synthetic and illegal drug that is highly addictive. Also known as ice, or crystal, the use of meth can lead to devastating physical and psychological side effects.