Generate a Zero-Valued UUID

Say you want a UUID of 00000000-0000-0000-0000-000000000000, but you just want to make one fast, without having to find out the number and grouping of digits. Here's a way to do it:

Generate a Version 4 UUID With Javascript

[sourcecode language="javascript"]
function uuid4() {
return "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx"
.replace(/[xy]/g, function (c) {
var r = Math.random() * 16 | 0, v = c == "x" ? r : r & 0x3 | 0x8;
return v.toString(16);
});
}
[/sourcecode]

From Mvc2.TaskUI by Jonathan Oliver.