The new Mac O/S Snow Leopard has recently launched.  I have finally finished testing it and it makes a huge difference.  The speed increase is noticeable and it can actually utilize more closely the Intel processors to their intended capability.  Its worth the upgrade if you have any doubts.  Prices range around $30 for the upgrade, so its not going to bust the bank.  MacMall has the snow leopard price drop coupon making it only $24.99.  If you have more then one Mac, then go for the family pack (5 users) for only $42.48 at macmall.  While your at the MacMall you can also check out the new iPod Nano with video.  If you pick up the new Nano from MacMall you can get a set of free Altec Lansing portable speakers.