Mac: Setting the default app to open a file on the Mac can be accomplished in a number of ways, including getting info on the file in the Finder and making your selection. If you want to get the job done quickly, just right-click on the file and choose "Open With" while holding the option key.

Mac:Want to quickly add an item to your the sidebar in your Mac's Finder windows? Press Command+T. Want to add it to the dock instead? Just press Command+Shift+T.

There are few things more aggravating than trying to watch a video when its audio is about one second too slow. Here's a quick fix for the problem in VLC.

Every Gmail user has dealt with this annoyance: you're writing an email, you copy and paste some text from another page, and the text's formatting comes along for the ride. It's not the end of the world, but then everything you type after that is formatted the same. Ugh. So now you do what? Keep the formatting? Switch to composing in plain text? Hunt for Gmail's default font and size?

Trying to get to a particular part of the map on your phone? Lifehacker reader Matt reminds us that Google Maps includes gesture shortcuts for zooming in and out.

Mac: Here's a great way to quickly forward a link to a web page you're reading: hit Command, Shift and "i" and an email message will automatically open with the page title in the subject and the link in the body.

Mac: Previewing a document in Mac OS X Lion using Quick Look? Want to open it in an application instead? You don't have to use the default application that Quick Look suggests in the top righthand corner of the preview window. Just click and hold down on the "Open with..." button to see several available options.

In the same way you can hold down the back button in Safari, Firefox or Chrome to access your browsing history, holding down the Finder's back button in Lion shows you where you've recently been.

Your spacebar is an excellent timesaver on your Mac if you know how to use it. One great use is open spring-loaded folders in an instant.

If you want a super-steady shot from your iPhone's camera -- or want to take a picture of yourself from a tripod -- you can actually use the volume button on your iPhone's headset to take a picture.

If you want to save the contents of the Mac OS X clipboard, or just don't want to bother with it at all, you don't have to. You can just drag text (or, presumably, any other media) from one app to another using the dock or even the app switcher.

Lion's resume feature can be pretty handy, but other times it opens a bunch of old windows when you least expect it. If you're tired of apps opening up all the windows you had open last time, you can stop the app from remembering those windows next time with Command+Option+Q.

With iOS 5, Apple finally brought tabbed browsing to Safari, but they did even more than that: with it, they added a shortcut to reopen tabs you've accidentally closed.

Mac: If you're a fan of the Stickies app on the Mac and want a really quick way to create sticky notes out of existing text, here's a keyboard shortcut that can save you some time. Just select any text from any source and press Command + Shift + Y.

Maybe you love Mac OS X Lion's new full-screen mode or maybe you hate it. Either way, you'll be better off knowing this little shortcut, because it can get you in and out of full-screen mode faster -- whether you want to be in it or not.

According to a statistic published in The Atlantic, 90 per cent of computer users don't know what Ctrl + F can do. As a result, we've put together a list of common, handy shortcuts and tricks that every computer user should know. If you have a friend or family member who could use a lesson or refresher, send this post along.

When you're in Google Docs and want to check the definition of a word, all you need to do is type the word (or select an existing one) and perform a quick keyboard shortcut. For Windows users, that shortcut is Control+Shift+Y. For Mac users, it's Command+Shift+Y.

We've discussed keyboard shortcuts to force quit or force quit the front-most application in the past, but if you have no desire to memorise a long keyboard command, this simple trick lets you switch between opening the Force Quit menu and force quitting the active app with one key.

Your iPhone's autocorrect feature isn't always perfect, sometimes to the point of humour, but it can be very useful. This is especially true when typing contractions, as your iPhone will take care of the apostrophe for you. The problem is, it doesn't work with words like we'll because well is a correctly spelled word. The solution? Make a purposeful typo.