I don't know if you have seen this, but dremd was working on an interesting project that might help. Check it out here:
Starting My A/C Seat project
My wife was also very thoughtful and picked me up a few of these seat covers recently. They were very reasonably priced and are a step up from the normal beaded seat cover. I haven't had a chance to put them in the car and try them. I'll be sure to write a full review once they are in. She is an A/C junkie (75 degees and that sucker is on
), so I really hope they work good.
Amazon.com: Wagan Universal-Fit Air Circulating Ventilated Seat Cushion: Automotive
None of these options are actually air conditioning, but direct cooling is much more effective than blowing air on you. I've read the OEMs are looking into in seat cooling as a way to cool down passengers. This allows them to downsize the A/C system considerably.