My two favourites:
-For this one you need somebody completely devoid of braincells (there was this girl... :whistle: ). we took her cell phone and switched the language from Slovene to English (and she hardly knows any english at all).
She quickly switched the language back, but every SMS we sent her - we sent in English claiming, that we've written it in Slovene.
She took the phone in for repares, because it automatically translated messages to English...
-At a small private party.
There were 5 of us at a small cottage in the mountains (the parents of one of them owned it). We had a little picnic there (barbeque lunch), and lot's of alchohol (naturally). So this guy (he drunk a bit too much) went in to sleep it off. He slept until it started getting dark. We went in and blocked out all windows - so there would be absolutely no light in there (there was no electricity anyway - we had some gas lanters) and pretended we're playing cards.
When he woke up (slightly hung over) he could only hear us play (and we behaved as though we can see normally), but he couldn't see a thing. We convinced him that he became blind from drinking too much. He was panicing and ran out (and he saw the stars... what a relief for him).
I got the idea for this one, from my dad - they did this to another guy while serving army duty - so there are times when my dad is really my role-model 
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