The "stats for nerds" page is also good entertainment (available from the task manager or by typing about:memory).
Not only will it tell you where all that memory is being used (Chrome isn't exactly lightweight), but it will also spy on IE and Firefox and let you know how much memory they are using.
And the task manager is amazing, exactly what I've been wanting.
(all the good stuff is under the Page menu, then the developer submenu. Took me a while to find).