Are you using Google Apps for your domain? Now, you can have a custom URL for your Google Apps addresses. For example, if you have host your email for your domain using Google Hosted email service, your login URL will be something like http://mail.google.com/hosted/yourdomain.com, or http://www.google.com/a/yourdomain.com. Now, you can make your own email login address e.g. http://email.yourdomain.com/.
All you need to do is just login to your Google service control panel, create a custom URL, and create/add a CNAME record.
You can have a custom URL for your other Google service e.g. Google Calendar.
