After my last trip to Costa rica I realized that I had lost close to 2000 shots due to my ISO setting causing noise. Since I have been home I have tried quite a few noise reduction solutions. So here they are.
All photoshop plugins that work on cs4 extended
Noise Ninja- worked for minor color caused noise when i didnt white balance but thats it.
Topaz Denoise- Worked amazingly for dark shots and is the best of the group
DFine 2.0- It worked ok for day shots but for night shots it was horrid
Noise monster- Didnt work for CS4 but worked fine with CS3
Topaz and Dfine2 works for Cs2 and beyond
noise ninja http://www.picturecode.com/
Each of them are $80-$100