if you want to use the same editor in linux, you can install KDE with fink and then install Kile, the latex editor for KDE. All have to be installed from source (enable "unstable packages" in fink commander) so it takes a while to compile. I'm doing that on my mbp with MacTeX 2007 and KDE as my X-window manager that starts when X11 starts. I think that Kile is much better than TeXshop (tabbed editing, word completion, insert symbols, section view on the side, etc) if you like to work in X11 a lot.