In playing more with Google Apps, I just discovered that you can use custom subdomain names for accessing services such as mail, documents and calendar. It's just a matter of logging into the Google Apps domain console -> Service Settings -> Service and under the General tab, clicking change URL under the web address.
Once you have your address set, you'll need to add a CNAME to your account (just as was done when creating the blog link in my previous article). And then, as they say, lather-rinse-repeat for all the desired services.
I'm still waiting for my domain changes to go through, but so far everything appears exciting. The only recommendation I would make is to make the CNAME changes about 24-48 hours before enabling the subdomain in Google. In doing so, you will minimize downtime waiting for the changes to propagate throughout the DNS system.