Google's rolling out a redesign of the Gmail compose functionality that will save heavy email users a lot of time. The new compose window won't take up the entire large frame of your Gmail anymore. Instead, it'll look like a larger version of the Gchat window that you're used to.
As Google points out, going back and finding information from other emails so that you can write the one you're working on is a huge time suck. The new floating compose window will allow you to reference old messages without breaking the flow of what you're writing. In addition, Google's tweaking the "To," "CC," and "BCC" address lines so that profile images of your contacts show up when you start typing in their names. Anything that cuts down on the amount of time we have to spend writing email is a winner in our book.
Google is launching a limited preview of the new features today. They'll be rolled out to everyone in a couple of months once all the kinks are ironed out. [Google]