The blog Ketchup-Mayo-Senf.de just released one validationdata key from an iPhone 4S. The key will only be valid for 24 hours. If you have your own SiriProxy Server already set up, you can just copy the key to your server (you have to solve a tiny puzzle first to get the full key). If you don’t have your own SiriProxy Server, you might want to copy the keys directly onto your iDevice with Sirious.

Thanks @kmsbueromoebel for the key!