Now, most of us know about the three finger salute that serbs use to signal serbian unity or nationalism
Well, meaning no offense, but I knew nothing about it until now and had I seen the picture you linked to I would have wondered "Why is he signing the number 3?" as that is the American Sign Language hand position for 3. We use some Signed English with our youngest as his speech is delayed due to mild Down Syndrome, so while I'm by no means proficient, I have worked with that language on a child's level for some years. http://library.thinkquest.org/11942/asl_num.htm
I found a source on the internet, which to be honest, did not look too reliable (was written by a catholic), that states that the three finger solute is a grave sin actually because it seperates the Holy Trinity and fails to show the unificication or the togetherness of the three entities. Now, this makes sense but the person also made a claim that something very similar was mentioned in the Bible itself (about symbolically seperating the Holy Trinity) and that it was punished by God.
Does anyone recall anything similar to this in the Bible? I certainly can't find anything to do with this.
Well, gestures and symbols have different meanings depending on the people or culture using them. It's not necessarily so that something done in one place means the same to people in another place.
That the article you found on the 'net was written by a Catholic does not necessarily mean that it is "unreliable", it depends on the knowledge and qualifications of that individual rather then what Church they belong to (and also there are some splinter groups that claim to such things as being the real Catholic Church and other umm unusual ideas, so until more is known, I see no reason to accept his/her assertions without question). Do you still have the link? Also, when the writer asserted that there was something in the Bible, did they provide a citation as to what book/chapter/verse? If not, it is an undocumented statement. Someone making an unusual claim should back it up.