One thing that's holding me back from using Google Apps is that they are generally damn ugly. You can use Mail.app to pull mail in Gmail down and get a nicer UI. I can pull my calendar down into iCal and get a nice UI as well. But in the end those web UI's are full of far too many buttons and links and just don't thrill me.
I've been using Fluid for my Google Reader and it rocks. I can now just hit RSS in Quicksilver and get my RSS feeds. Using the scripts from userscripts.org I now get: Growl notifications of new posts and a count in the dock of new posts. Today I grabbed this script: http://flingmedia.com/articles/making-google-reader-for-fluid/ and that applies a custom stylesheet. It makes the reader look like the screenshot below. Weeee!