Do you own an iPhone 4S and really wish Siri worked for you? I feel your pain. It doesn't make sense that Siri works exclusively for the 4S. It's just not fair. Ok, now that we are over that, what can we do? How about hiring her 1st cousin? Let me introduce you to SpeakToIt ($1.99). Not a very appealing name, I agree so if you ask her what her name is, she says it's Sam, just Sam. I refer to her as a 1st cousin because she uses the same voice recognition that Siri uses, Nuance. Understand though that she is not as talented as her cousin. She can find coffee and gas nearby, give directions, send messages and e-mail and a number of other things Siri does. She is also able to update Facebook and Twitter, which Siri won't do.
In my tests, the voice recognition is not as good as Siri, but that may just take some practice with her. I also had a little trouble getting directions right, it took a couple of tries. This app has been on Android for a while and just came to the iPhone so my guess is that updates will iron out what few bumps there are.
If you don't have a 4S, want Siri and can't upgrade but really want Siri, then give Sam a try. Two bucks is a no brainer.