[X4U] migrating from one computer to another

[Kansas Territory]

I've been using a G4/450 for several years now.  running latest version 
of OSX.
Got a new/used Dual G4

Is there some simple way.. I can take what I got on the old G4.. and 
move it ALL over to the new computer..
I spent so long getting the old computer JUST HOW I WANT IT.    And the 
idea of starting over just really bothers me.

I used to do this all the time with OS9,  reformat a drive and start 
over. But with OSX, I've been updating this old G4 since OSX came out.. 
one update on top of another
and it's been working great.    Just want everything I got on the 
faster computer.

Any suggestions ?

Kansas