I play pool with my girlfriend.  I hate it, but she seems to have fun beating me.
Ha! This is known as billiard sports, which is played with a cue stick used to strike billiard balls around a table.
cool.  I wonder who invented the game of pool?
The earliest known reference of the game was written in the 1588 inventory of the Duke of Norfolk.
wow.  thats cool.  what country is that?
It is British. 
wow.  do you think they still play pool in britain?
Definitely. British and Australian english refers to "billiards" as the game of English Billards, while american or canadian english refers to a particular game. 
wow i wonder what pool competitions exist today
There is the WPA World eight, nine, and ten ball championship.