I´ve been messing around with Photoshop CS3 and I´ve found a couple of things I´d like to share with you.
In versions of PS prior to the CS2, only one layer in the layer palette could be selected at a time. Now, there´s the possibility to select more than one layer and work with them alltogether, in the typical ctrl+click way to select and de-select layers.
This is great, but that combination (ctrl+click) was previously used to select all layer´s visible pixels. So now, how is this thing done? Well, after 15 minutes trying, searching, and desperating, I´ve realized it´s the very same thing, but clicking in the layer´s thumbnail instead of any part of layers entrance.
Second trick I´ve found here:
HOWTO flatten, or rasterize all layer´s effects:
If you have applied some effects to a layer, all of them keep editable at all the time. This is also great but if you need at some time to "apply" all that effects, rasterize them in the layer and reset all the effects properties, so you can work again with the modified layer "from scratch", there is no obvious option to do so.
A very easy way to do this, is to create an empty layer and place it just below the layer you want to flatten. Then merge that layer down (ctrl+E) to the empty layer you just created and voilá! all the effects get applied and disappeared.