Gradient overlay to ALL

Im doin a poster, and i once and for all need to ask this question which i have been woundering about for a quite some time: can I apply gradient overylay to many layers at the same time? So that the color continue to change from light to dark through the layers?
I have attached the poster, and you can see i have added the name of the consept, dadarock, in many layers to get the effect i want. Whats left is for me to ad some gradient overlay so that it goes from light, to dark, up to down. I can do this one layer at the time, but this will take a looong time. Is there a trick to get this effect and the text as a whole?
you can see the poster here: http://www.photoshopforums.com/post57053.html#57053

Hi dude

Apply a gradient overlay to single layer. Right click on the layer and select "Copy layer style". Now, select the layers on which you want to apply the effect and on right click select "Paste layer style" and this will apply to all the layers you have selected.

Hope this helps,

Cheers!

Maneet Puri
Web Design Company