I have been loving this app called MailTab.

I don’t check my personal g-mail as much as I do my work mail all that often, but when I do, it is right there, one key command away. And when open, it responds to all of Gmail’s existing key commands. The window is also size-able.

I really thought I would find an app like this annoying, but actually, it is proving to be really great a being available when you want it, and getting out of the way the second you don’t need it. Isn’t that a quality that you would like to see with more apps?