MacUser's Andy Ihnatko's put together a list of what he's determined are the best Mac OS X features most people don't seem to use (or aren't even aware of in the first place).

First on his list are OS X's Speech Commands. As Ihnatko points out, Macs come standard with a whole slew of voice commands for such functions as navigation and application switching. Plus it's a cinch to add new commands, as Speech will open any alias, file, folder or application that's in its Speakable Items folder when its name is spoken. But that's not all - put AppleScripts and Automator workflows into the Speakable Items folder and you'll be able to get your Mac to do long, complex instructions - perhaps even more complex ones than you may think are possible.

Next up is Sharing. Bet you didn't know that any USB printer connected to a Mac in a network can be made available to every other Mac on that network. Or that a Web Sharing feature allows Macs' files to be accessed by any device, even smartphones. Or that network connections can be shared via AirPort. There's more of course; that's just the tip of the iceberg.

And then there's Spotlight - more specifically, Spotlight's Smart features, which automatically organize everything for a user without even needing to be asked. Spotlight automatically indexes files and inserts references to them in Smart Folders set up in the Finder. Everyone who uses a Mac makes use of Spotlight, but very few of those who do so ever go beyond the basics - and that's a real pity.

Ihnatko's top pick - for him the most 'underused and unappreciated' OS X feature - is the Help menu. It's something even experts are forced to do one time or another. As he says, "Hitting Command-? is like embarking on a pilgrimage. ItÂ?s humbling, but it undoubtedly strengthens the soul."

I've been a Mac user for years now - switched to OS X just a year ago - and I have to admit I'm guilty of the sin of not having learned more about what it can do for me. Any fellow Mac users out there who can say the same thing?