var arr = [1,2,2,3,4,5,5,5,6,7,7,8,9,10,10];
function squash(arr){
var tmp = [];
for(var i = 0; i < arr.length; i++){
if(tmp.indexOf(arr[i]) == -1){
tmp.push(arr[i]);
}
}
return tmp;
}
console.log(squash(arr));
Working Example http://jsfiddle.net/7Utn7/