Gmail has added yet another interesting feature to their email service. Known as Inbox Preview, this feature allows you to see your 10 most recent mails while you wait for the Gmail to load. You can turn it on from Labs tab under Settings.
The preview is basic and very similar to Gmail Inbox. Unread mails are shown in bold characters and while all the read mails are in normal font.
Here is a screenshot.
This feature may not be of much use to people with fast internet connections, but it is really beneficial for people who have to cope with slow internet/ limited internet access.
Alternatives
Gmail also offers a basic html version for slow internet connections.
You can also try the Gmail Manager Plugin for Firefox which scrolls a nice little preview up whenever a new mail arrives. You can also add audio alerts for new messages.