Following my comments to Wolfgang on the "Sarah the Whale" thread I tried the useful phrase on Babelfish with results below. Native speakers might like to correct it and add other languages, before we next head down to the Mudcat Tavern:
English: My friend will pay for the drinks
French: Mon ami peyera les boissons
German:Mein Freund zahlt fur die Getranke
Italian:Il mio amico paghera le bevande
Portuguese:Meu amigo pagora pelas bebidas
Spanish:Mi amigo pagora las bebidas
Greek:(would be something like)To filos mou tha agoraza to pioto

[apologies for loss of accents and umlauts]