uniq.js

function uniq(arr, f) {
    var r = []
    var h = {}
    var f = f ? f : JSON.stringify
    arr.forEach(function(i) {
        var v = f(i)
        if (!h.hasOwnProperty(v)) {
            r.push(i)
        }
        h[v] = true
    })
    return r
}