The Fizzinator

The Doctor's "special drinking straw" was a straw the Eleventh Doctor held in a Utah café in 2011.

While talking to Amy and Rory, the Doctor explains that he got up to go get his special straw from the TARDIS, to add more fizz to his drink while he waited to figure out who sent him his invitation. (TV: The Impossible Astronaut)

Behind the scenes
During his time in Area 51, he drank a lot of soda with it to calm his nerves due to his growing impatience. He called his special straw "the Fizzinator". (REF: The Brilliant Book 2012)