While working, I now actively use Spaces to maximize my work space. I use Quick Look VERY actively, especially for videos and text documents (and now folders). I use Quick Look also by putting things in "thumbnail" view, and seeing the custom previews. Popping open PDFs instantaneously with the spacebar is worth the price of admission.
Coverflow is fantastic for whipping through a directory of images or movies. I've set up Time Machine, and for the first time I'm backing up regularly... although, its more than an anti-climax, as you set it and forget it. Until I lose a file, I won't appreciate it. I'm still watching it for what I still should EXCLUDE. I already exclude my download folder, but my desktop habits aren't very good (often contains files I don't want to back-up).
The tabbed terminal with translucent black background is awesome (I use the "Pro" theme). I'm also getting some great use out of the data-detectors in Mail. I've found myself creating appointments and To-Dos frequently inside of Mail, and reconciling their place amongst other events in iCal. I've already used the new iChat with a friend I'm collaborating with on a animation pitch package. We actively dragged sketches into and out of the window, and its was pretty good, although my broadband connection couldn't sustain a lot of it over time.
There's SO many things in Leopard to feel great about, I'm under the impression that if someone ISn't getting much more out of it than Tiger, then that might say more about their individual personality (and how quickly they can adapt to new things) than it does about how useful Leopard's advances are. I sware... I'm ACTIVELY resisting the urge to create my first Widget clip. As a web designer, I just despise the idea that Apple is facilitating the consumer ability to chop up people's webpages. I can't imagine I won't eventually find something worthwhile to use it on though.
~ CB
