Crossfading available in ipod touch?

I have an ipod touch 3G and an ipod nano 5G.

in the nano, i have an option to crossfade between songs, but in the touch i dont see that option.

i did a bit of research, and came to know that the iTouch doesnt have that option, BUT it can be enabled with itunes (something called gapless playback).

so how do i do it?

do i have to do it for every song individually, or each album, or each artist?

i also have a playlist, so do i have to enable crossfading in my normal ipod touch music library, and THEN go to the playlist and enable them individually?

or can i just do it once and get it done with?

thanx !