"Cheers" generally means 'thanks', but it can also mean "Goodbye".
"Here Johnny I brought along another sandwich 'cause I know you can't leave the office today..."
"Oh cheers Adam!"
Here in Australia we do use a lot of Britishisms for obvious reasons. And I have heard 'Cheers/cheerio' used on occasion, by young and old alike. Although folks of my generation and younger tend to use 'cheers' more.
Speaking of Australia, after all the Crocodile Dundee in the late 80s, it became fashionable for Air Traffic Controllers here in the States when handing you off, to say G'day over the radio!