Lipstick

Lipstick was an item used on Earth by (predominantly) females as a cosmetic item applied to the lips. (TV: The Visitation) It was occasionally used to write messages with in lieu of other writing materials. (TV: The Girl Who Waited) Some lipstick, such as that owned by River Song was impregnated with poison or hallucinogenic substances. (TV: Let's Kill Hitler, The Time of Angels, The Pandorica Opens)

Lipstick lookalikes
Sarah Jane Smith was known to carry a device called Sonic lipstick. It was essentially a sonic screwdriver disguised as a stick of lipstick, and was a gift from the Tenth Doctor. (TV: Invasion of the Bane, et al.) She had at least two. (TV: Enemy of the Bane)