Is it possible to install a new trackpad in an old macbook?

so i am curious if i can install a trackpad from a new macbook pro or air into an old 2007 or 2008 macbook, if possible im going to buy a macbook off ebay and save myself $600

read the first comment in this video http://www.youtube.com/watch?v=Eop9CvYwhes
By the way, i am new here, ill make an intro soon.

EDIT: Has anybody tried this? http://blog.lmjabreu.com/123
but i like the full huge click pad on the new macbooks, so it would be nice if i could put a new trackpad with integrated button than have a separate mouse button

 

Well, I won't be buying an older Mac now that mountain lion dropped support for em, I'll just wait till my summer job and get the 2011 13" air.