First one said I called and answered their trivia questions correctly (which I never did) and so I've won a free two night stay in Vegas, and tickets to the show Lovers or Losers in downtown Las Vegas.
Second voicemail was similar. Nothing about trivia though, they said I called in December and I've won the same prizes.
Of course it's all fake. Sounds like a boiler room. I'll call them back when I have some free time and see how much money they expect people to shell out for this scam. They sound like they are in the US since none of the callers have thick accents and seem to speak perfect English.