Chef is right, this has been covered to DEATH! But to be a nice guy, I'll give you a quick answer. Search if you want details. The answer, unfortunately, is a resounding NO. I've got an '03 SE with the RF HU, just like yours and it does NOT have an AUX IN. The only way to get one with the HU we have is to replace the HU. Short of that, the only other option we have is an FM modulator, which works reasonably well depending on which one you get.
Sorry for the bad news, but to quote, "Just the facts, ma'am!"
-G-