I would like to take back everything I said in my previous posts about Yahoo! Widget Engine!  After switching from Google Desktop briefly last week to Yahoo! Widgets, I saw the performance of my computer slowly get worse.  I am not sure how much RAM each one consumes but if I were to guess then Yahoo! Widget Engine takes much more.  Also I find that the interface is kind of cumbersome because unlike Google Gadgets, Yahoo! Widgets sit on your desktop.