The five hints Apple is working on a tablet

Snow Leopard leaves prints

Though Apple isn't saying whether it's working on a touchscreen tablet, the company may have shown its hand at its Worldwide Developers Conference last week.

Of course, the Apple tablet has become the Apple press corps' version of a Bigfoot hunt. Some believe the evidence is overwhelming. Others are, well, underwhelmed. And Apple doesn't discuss products before it's ready to.

However, based on the features demonstrated at the developer conference last week, the newest version of the Mac operating system, OS X 10.6, dubbed Snow Leopard, could turn out to be the most touchscreen-friendly Mac OS the company has ever built.

Snow Leopard won't be available until September, and so far, Apple does not sell a touchscreen laptop or tablet. But some of the features in the upcoming OS at least show a path on which Apple could be headed toward offering a larger touchscreen device.

At the developer event, a list of new features of OS X 10.6 was rattled off by SVP of software engineering Bertrand Serlet. But most of the upgrades to the operating system from the previous build, OS X 10.5, known as Leopard, are gentle tweaks aimed at easier usability and faster processing, things the average user may or may not notice.

After a closer look, however, the unifying theme of several of the new features of Snow Leopard is that they're now extremely easy to navigate without a keyboard, or without a lot of mouse clicking. That also happens to be one of the keys to a successful mobile interface: keeping steps to opening applications and performing tasks to a minimum.

Expose in dock Starting with the Finder, the addition of Expose to the dock is a great example. Expose is a feature that is used for organising all your open windows at once, or just the windows from a particular application you were running. Putting Expose directly into the dock now cuts out the need to first switch to the specific application you want before activating Expose. It also cuts out the need to use a keyboard, or use a trackpad gesture to call it up. Clicking and holding an app's icon will bring all windows open that are associated with that program to the front. Being able to tap and hold on a touchscreen would make it that much easier.

Stacks There's also Stacks, a feature that keeps shortcuts to chosen files in the dock, which has been updated to be more useful without forcing users to enter the Finder. In Leopard, the amount of thumbnail previews of files shown in a stack was limited, and to see the all files, you had to go into the Finder. Now in Snow Leopard, all items in Stacks can be viewed simply by dragging the scroll bar, precluding the need to open the Finder. That might seem like a small change, but it's important if you're browsing with just a finger on a touch-sensitive surface.

QuickTime X The new version of Apple's video application QuickTime is also more touch-friendly. The player controls (play, pause, forward, backward) are now quite similar to what's found on the iPhone. Also, in order to edit videos, there's a ribbon timeline of scenes from the video that appears under the player. The ribbon can be moved forward and backward in time for editing just by dragging. The same interface is what users of the new iPhone 3G S will be using when they want to trim video clips they've captured on the device. Prior to this, you had to set the beginning and end points with little arrows that provided no indication of what segment of the clip you were editing besides the time.

Freehand drawing And then there's the addition of freehanding via the touchpad. Apple said Snow Leopard will allow users to draw Chinese characters freehand onto a Mac notebook track pad, and the OS will predict characters for faster writing. This feature could...

...clearly transfer from trackpad input to direct onscreen input if Apple engineers wanted. They already have a similar feature in the iPhone for Chinese characters based on the technology from Hanwang.

Safari 4 updates New Safari 4 features would also accommodate easier navigation by touch. The new Coverflow option to browse through past sites visited as well as sites you visit most often would be easy with the drag of a finger. And on a screen larger than an iPhone, the effect would work marvellously.

These are just a few of the feature upgrades of OS X 10.6 that seem it indicate a trend toward touch capabilities.

True, Steve Jobs said at an Apple event last fall that putting touchscreens on traditional laptops "hasn't made a lot of sense" to Apple. His point is a good one: even companies that embrace touchscreen laptops admit that it's an awkward posture to sit and point at a laptop screen. HP's CTO of its PC group, Phil McKinney, has indicated that's why the company's Windows touchscreen laptops are convertible to tablet PCs. But Jobs' comment doesn't rule out a different form factor with a touchscreen, like a tablet.

While it would seem like Apple could use the ready-made iPhone operating system for a tablet instead of a touch-friendly version of Mac OS X users, that could limit the device. Most users expect the freedom of having a Finder and the ability to download directly from the web and not through the App Store only, as with the iPhone and iPod Touch.

If Apple does end up making a tablet that were to run Snow Leopard, or some version of it, that means it probably wouldn't be announced until after Snow Leopard's official release in September. Others have speculated it won't be ready until at least early 2010.

CNET's Josh Lowensohn contributed to this story.