Millions of users rely on GMail, the free ad-supported webmail service from Google, as a secondary -- or even primary -- e-mail account. With nearly eight gigabytes of mail storage, effective spam filtering, built-in chat and phone calling for free (in the US and Canada), a threaded "Conversation" view and mobile access, GMail positions itself as a viable alternative to "regular" standalone e-mail clients. But what if you could have both? Mailplane gives users GMail in a standalone application. Is it the best of both worlds? We'll find out in our review.