The Beta channel of Chrome for Windows, Mac and Linux has just been updated to include a refreshed style of account switcher and a brand new Guest Mode. Chrome Beta 38 refreshes the look entirely of switching users, making it easier to share a computer using Chrome. You'll now get a quick drop-down menu from the system bar that lets you see who's signed in, quickly switch users or open an incognito window.
Just as before, when you have multiple accounts on a Chrome install you have separated silos of user data, but now you'll have a smoother way of switching between available accounts.
The biggest deal here is the inclusion of a new Guest Mode, though. An extremely valuable feature previously available on Chrome OS, Guest Mode lets you open a brand new incognito-style window that is completely separated from your browsing data. Browsing data from the Guest Mode session is completely deleted once that window is closed, and you're then free to switch back over to your main account and pick up where you left off.
It's easy enough to switch over to the Chrome Beta channel if you want to try out the new account switcher, but you can also rest assured that the new interface will make it over to the stable channel in short order.
Source: Google Chrome Blog