Add subqueries example.

examples/subqueries.js

@@ -0,0 +1,15 @@
+// Sending commands in response to other commands.
+// This example runs "type" against every key in the database
+//
+var client = require("redis").createClient();
+
+client.keys("*", function (err, keys) {
+    keys.forEach(function (key, pos) {
+        client.type(key, function (err, keytype) {
+            console.log(key + " is " + keytype);
+            if (pos === (keys.length - 1)) {
+                client.quit();
+            }
+        });
+    });
+});