A major operating-system release is filled with all sorts of changes beyond the handful of features a company advertises to catch your interest. In the case of Mac OS X Lion, I keep running into little surprising details.

I had to gloss over a lot in my review of Lion (Personal Technology, July 23) so as not to overwhelm my ever-patient editor, so in this column I want to take a look at a few Lion details that you might overlook.

Lion Recovery Disk Assistant: Lion is available only as a $29.99 download from the online Mac App Store, which means there's no physical media such as a DVD to use in case something goes wrong and you can't start up the computer.

Lion does include a hidden Recovery HD partition as a replacement (start up with Command-R pressed, or hold Option at startup and choose the Recovery HD as the startup disk). But that's not helpful if your hard drive is damaged or nonresponsive.

An installer on a USB drive will be available for $69 later this month, but that's a steep price to pay just for a disk that will boot your Mac.

Last week, Apple made it a little easier to have backup utilities on hand by releasing the free Lion Recovery Disk Assistant (support.apple.com/kb/DL1433). When run under Lion, you can use the utility to create a Recovery HD partition on a USB thumb drive.

Use it to run Disk Utility on a suspect disk, or even reinstall Lion; however, the recovery disk doesn't include a full Lion installer. You still need broadband Internet access to download a new copy of the Lion installer.

(There's also a better way, as my colleague Glenn Fleishman pointed out in the last Practical Mac column (July 30), that involves making a full installer on a USB thumb drive using the installer you download from the Mac App Store.)

About This Mac: Looking for a quick way to determine how much free space is on your hard disk? Apple revamped the About This Mac window that's much more helpful. Go to the Apple-icon menu and choose About This Mac to reveal basic information, then click the More Information button.

Click the Storage item at the top of the window and you'll see the disks connected to the Mac, including an iOS-style bar graph that breaks down how much space is used by audio, movies, photos, apps, backups, and other data.

Quick Look: I know it's been two full releases of Mac OS X since Quick Look was introduced, but I still marvel at how useful this seemingly limited demo feature is. Select a file in the Finder and press the space bar to view a preview of the file's contents.

In Lion, Quick Look functionality has spread to other areas. Position the mouse pointer over a URL in a message in Mail and click the little gray Quick Look URL button that appears to preview that Web page.

Or, when searching for something using the Spotlight field in the menu bar, hover the mouse pointer over a search result to view it in a Quick Look window.

The Quick Look window that appears in the Finder also has a new feature. A button appears with the name of the default application for that file type (for example, Microsoft Word for a .doc file) to quickly open the document in that app.

But if you click and hold the button, you can choose to open it in other apps that support the file type (such as Pages).

Of Mice and Magic: When Apple released the Magic Trackpad, I saw it as a mouse replacement. I wasn't crazy about it as a primary input device, but with Lion, I think it makes a great secondary device.

Using gestures in Lion is addictive — two finger scrolling is now second nature to me, and I'm getting used to two-finger swiping to go to a previous page in Safari. Another handy shortcut is to double-tap a word with three fingers to quickly bring up its dictionary definition.

Lion did make me change one long-ingrained behavior. I've used Kensington multi-button mice for years, but the creaky Mouseworks software no longer works.

I wasn't out of luck, though: I downloaded the $20 USB Overdrive (www.usboverdrive.com), which lets me configure button clicks as I like them (double-click for the right mouse button, and Control-click for the thumb button).

And here we are again, at the end of my allotted space and having covered just a handful of details that might get overlooked. There are plenty more to discover in Lion.

Jeff Carlson and Glenn Fleishman write the Practical Mac column for Personal Technology and about technology in general for The Seattle Times and other publications. Send questions to carlsoncolumn@mac.com. More Practical Mac columns at www.seattletimes.com/columnists.