There was a time when iChat fell distinctly into the category of Why Did They Bother, because, even on Macs, AIM was king. You had to be a total Apple loyalist to use old, featureless iChat. Those days are dead and buried.

As soon as iChat added folder hierarchy - which for quite some time was the killer feature that kept it under AIM, in my opinion - I dumped AIM and never looked back. The leap to iChat AV and easy-as-pie video or audio chatting seemed like the pinnacle for the concept. But the new Leopard iChat turns the formerly frill-less mini-app into something much grander.

The silly bit of the new iChat is the crowd-pleasing background feature. While live chatting, you can put yourself over some ridiculous pre-built background (like a serene waterfall or a shot of the Eiffel Tower). You can also drop in any image of your own, and yes that includes your own movie files. Here's Tony and me testing it out.

The look is okay, considering. It ain't your local newscast's chroma-key wall, but it does the trick. And anyway, it can only get better and iChat continues to develop. To achieve the effect, iChat tells you to "step out of the frame", at which time it memorizes whatever is behind you. When you return, it assumes that anything that is old pixels (IE, anything not you) can be dropped out in favor of the video loop. As you can see, it's spotty.

The best bit is that the "step out of the frame" demand always inspires you to dive like a madman for the floor.

But that's fluff. The real awesome in iChat is the screen-sharing and file-sharing abilities. Screen-sharing lets your chat partner move your mouse and use your computer. Computer screens have been a single-person, boxed-world experience for so long that when you try this out you can hardly believe it's happening. During the thirty seconds that I let Tony share my desktop, he dumped my web browser to another Space, tossed all my windows offscreen, and IMed Josh using my account.

The new file sharing feature lets your chat buddies view just about any file you have. I made Tony read the Kingdom Hearts Card Game manual PDF, view a plain text file of my Animal Crossing friend codes, and watch whatever movie files I had laying around. You just drag the file onto your chat window. Yes, previously you could send somebody a file through IM. Or you could drop a picture into the IM window. But being able to click through pages of a PDF in a chat? Well, we're officially beyond calling this a simple "chat." This is a goddamn tool now. Between screen-sharing and file-sharing, I'm not sure I even need to come in to the office anymore.

There's a lot of stink-talk about the new look for the Dock. It's sort of 3D now, with a gratuitous reflection on it. I will agree that it is weird to position 2D icons on a 3D space, but I don't really have a negative opinion on it. Eh. Did I prefer the previous, flat look? Yes. Am I more annoyed by the newly transparent menu bar at the top of the screen? Absolutely. At least the dock goes away 99% of the time.

One teeny thing that I do hate about the dock is the blue LED light thing that the Dock uses to show which applications are open.

I really like the way Docked folders open up into a big icon-based grid, especially now that icons tend to always be a live preview of the actual document, instead of some stupid generic app logo.

Spaces seems like a really smart way to organize stuff, particularly for folks like me who tend to leave a half dozen things running at the same time. I need to commit some time to creating my personal Spaces. Spaces, like Expose, is the kind of feature that a Windows user never gets, because it treats the apps and windows like actual physical objects, rather than just pixels painted onto a flat wall.

I should also seriously look into Time Machine. It sounds like the best backup tool ever made, but you need a redundant drive to use it. I will need to buy that extra drive.

QuickLook is instantly useful. It's in my default window view and probably already been used a couple dozen times. Between that and the new smart icons, you'll never have to boot a file to find out what's actually in it. QuickLook even runs the movie without opening up QuickTime.

The new Front Row is nice, although I do miss the "there goes my desktoooooooooop" effect when it starts up.

Safari lost all of my favicons. That sucked, because my bookmark icons all defaulted to that blue globe. Staring at the sea of Earths, I realized just how much I relied on the favicons to instantly locate specific bookmarks. So I've had to re-establish the icons as I go, but I have grabbed the opportunity to prune out old websites that I haven't visited in years.

Safari's new WebClip thing is supremely cool. I've already made Dashboard widgets of my webcam, Clark photo, and random photo... so it's like going to fourhman.com without actually doing it.

Mail finally looks like an Apple product! Hoorah! (Of course, I couldn't care less about the dopey email themes they added.)

There's the usual X.X screensaver additions... Word of the Day does what you would expect although Arabesque does not. The photo-based screensavers got one hell of an upgrade... first, there's a gorgeous collage option, where your photo collection falls onto the screen in a pleasing pile of Polaroids.

But then there's the truly amazing mosaic option, which literally creates those fancy million-pictures-make-one-picture out of your own iPhoto library. It starts with one fullscreen photo and then slowly zooms out until it makes another one, a cycle which then repeats while you pick your jaw up off the floor.

So, yeah, wow.