I've read some and tried Smart Objects, but not completely understanding why I should be using them, and I feel like I should be. Can anyone give me some pros and cons to using Smart Objects to to adjustments in PS and the workflow changes I'll encounter?
Process a file in Lightroom - then when you have done everything you can in Lightroom export it to CS3/4 as as smart object. Make some layer adjustments - anything will do, whatever you might normally do to improve an image. So now you have your smart object layer and a few adjustment layers.
Now double click the smart object icon on the layers palette and it will open up camera raw with all your LR adjustments respected. You can make any additional changes to the RAW file now.
Now that is way cool and very handy.
Jeff Schewe gave a great example in the LR 2.0 tutorial where he shows how to dual process an image [process for shadows and then for highlights] using just one original RAW file and smart objects. Worth checking out.