diff --git a/src/util/uid.js b/src/util/uid.js
new file mode 100644
index 00000000..532f9e9b
--- /dev/null
+++ b/src/util/uid.js
@@ -0,0 +1,29 @@
+/**
+ * @fileoverview UID generator, from Blockly.
+ */
+
+/**
+ * Legal characters for the unique ID.
+ * Should be all on a US keyboard.  No XML special characters or control codes.
+ * Removed $ due to issue 251.
+ * @private
+ */
+var soup_ = '!#%()*+,-./:;=?@[]^_`{|}~' +
+    'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
+
+/**
+ * Generate a unique ID, from Blockly.  This should be globally unique.
+ * 87 characters ^ 20 length > 128 bits (better than a UUID).
+ * @return {string} A globally unique ID string.
+ */
+var uid = function () {
+    var length = 20;
+    var soupLength = soup_.length;
+    var id = [];
+    for (var i = 0; i < length; i++) {
+        id[i] = soup_.charAt(Math.random() * soupLength);
+    }
+    return id.join('');
+};
+
+module.exports = uid;