it's definately not an island thing.... peopl ein the uk do it as well.... it's rare to see it in the states tho..

i started doing it awhile back.. can't taste the tobacco if it's done right and it helps the joint burn better (even if you're the best fucking roller and there's no problem with the way it burns, it can always be better) also helps to fatten it up some, not that i care so much about that, but it's a nice addition.