I was going to write a Beginner's tutorial on using the HDR (High Dynamic Range) function in Photoshop CS3.
But based on Bryce's recommendation, I downloaded and installed Photomatix. (Free trial download, then $99.00 to register) I think I like it. Alot. Give me a few days to play with it, then I'll report back.
I'm a registered owner/user of Photoshop CS3. I also own/use Photoshop Elements 5. This might be heresy, but I could see an agent/property photographer getting by with Elements($72.99) plus Photomatix($99.00) instead of Photoshop CS3($629.99)