Okay, when I first got my Rex last summer, the A/C didn't work. Took it into a dealership and after almost booking my car in for the day, they solved it in 30 seconds - fuse not connected. (Apparently they ship that way and the dealership I bought it from didn't hook it up, no biggie they did everything else right)

A/C worked just fine for the rest of the summer and of course I didn't have any need of it in the winter - I live in WA not CA. :)

Got back into a hot car this afternoon and turned the heat dial to max cold, blower on full, hit A/C - nada! Played around with the controls and at max cold I was getting ambient temperature, at mid-point I was getting hot and at max hot I was getting 'winds of the Sahara'! :rolleyes:

Anyone got any smart ideas? I'm not sure which fuse they tweaked last time or I'd go check that next. I had it in for service at a new dealership (well new to me) a couple of weeks back but that was just a 7,500 check, change and rotate and I have a sneaking suspicion they did more - I noticed a heck of a difference in driving after the oil change.. ECU reset maybe? I also have a sneaking suspicion somebody there took it for a little spin but I can't prove anything. :(

Bonkers.

It doesn't sound like the compressor is running, you can confirm this by looking and listening when you turn the AC on. You should hear a click or clunk when the compressor engages and if you look under the hood you should see it spinning. Also the radiator fans should run when the compressor is running.
If the compressor isn't running and it was the last time the AC was used, the most likely reason is a low refrigerant charge in the system. The usual reason for this is a leak someplace. There is a pressure switch that protects the compressor from engaging if the charge gets too low.
If you're still under warranty (at 7500 mi. sounds like you are) have the dealer check the system over. If the charge has leaked out due to a loose fitting or something similar it should be covered. Be aware though, that if they find the leak was caused by damage, such as a hole in the condensor, you will have to pay for the repair.

good call... i had mine looked at and it had too much pressure. that will cause the unit to turn itself off to prevent burn-out

Yes there is a high-pressure cutout as well. However if the system is not turning on at all I would suspect low pressure or a total loss of refrigerant as being more likely.
Either way the best course of action is to have a dealer or shop put gauges on it and see how much charge is (or isn't) in the system.