Oh... wait... actually I have.
I had the tiniest sip, that was probably about 3 drops though.
It was NYE, I was 17 and I was at Surfer's with 2 friends. Some older guys (I'd guess about 30-ish) convinced my friends to go with them to their hotel room... I tagged along because it was that, or be abandoned in Surfer's.
Anyway, they asked if we wanted a drink, but didn't wait for a response. I tasted, and it was supposed to be coke and some sort of gross spirit (rum, probably...ew), but I'd say most of it was rum. I could taste no coke.
I went to put it by the bench, and saw crushed powder on the chopping board and some full tablets too. No idea wtf they were, but I didn't drink my drink so I didn't care. I don't think my friends drank theirs anyway.
I locked myself in the bathroom while my friends went to the bedrooms with these guys and called a friend - told her exactly where we were in case something happened to us. Luckily, other than my friends skanking about, nothing happened.