For those who read Gmail via its Web interface, including in Mailplane, Google has released a Gmail Labs feature called Preview Pane. It gives Gmail a vertical interface with labels on the left, a vertical list of message summaries in the middle, and the main conversation display pane on the right. It works best with wide screens, though if you have a tall screen, you can switch it to a horizontal split instead of a vertical split. The approach is much more like Gmail’s tablet interface, and in turn like Mail on the iPad. follow link
Adding Links in Snow Leopard's Mail
Apple Mail in Snow Leopard now has a Command-key shortcut for adding a link to an email.
If you use plain-text email, this will not be helpful at all, but if you send styled email, it's a nice shortcut for adding URLs to your email messages. Simply select the word(s) you want to make into a link, press Command-K, and enter the URL to build into the link.
Gmail Gains Optional Preview Pane