So I was looking for a way to use Siri on my iPhone 4, but didn't think it was going to be feasible. After some searching I found Rainstone.co and couldn't be happier. I now have Siri running on my iPhone 4 thanks to Rainstone. I'm new to jailbreaking and really want to thank the guys over there for making this so easy. You have to add their repo: http://repo.rainstone.co/ and then you can install rainstone siri for 5.1.x in cydia. Their server is incredible and is only $15 for a lifetime spot. I tried using free proxies and others with no luck but with their server my Siri is running faster than my friends who has a 4S. You can get that from their website: http://www.sinfuliphone.com/showthread.php?t=10000222 The best part of all was the support. Being new to jailbreaking I really was having trouble and kept reading about different things but when I discovered the original post on Sinful iPhone it had the co-founder's iMessage, so I messaged him. He helped me through the entire set up! His iMessage email is: email@example.com All in all if you're trying to find an easy way to get Siri on your iPhone that isn't a 4S, or your iPad or iPod check these guys out.