When you select a zip archive in the Finder, and press the Space bar, the BetterZip QuickLook generator will show a graphical display of the contents of the archive. If you don't want to use the command line, and want to see what files an archive contains, this is a great way to do so.
Agile Tortoise's Drafts is a nifty tool for writing texts and doing things with them on an iOS device. I use it mostly for the more comfortable writing environment, and send texts as emails or tweets, but there's an entire sub-culture that's been hacking Drafts to do many things. (Check out the Drafts actions directory.)
David Sparks posted an interesting use of Drafts (credited to Milosz Bolechowski; I couldn't find the original on his site), together with noodlesoft's Hazel - a tool that automates tasks on your Mac - to put a Mac to sleep. In essence, Hazel looks for a file named "MB sleep" in a the Drafts folder in his Dropbox folder; when it finds that file, it puts the Mac to sleep with an AppleScript.
I think you might be able to do this with folder actions as well, but I'm not very good with AppleScript. So if you can, feel free to post a script in the comments.
You recently published a hint explaining how to open a new Finder window in the same folder as the frontmost window, using an AppleScript. Here is an easy way to do the same thing: no Applescript, no special apps needed.
In the Finder, make sure the Path Bar is visible (View > Show Path Bar). The current path is then displayed at the bottom of each Finder window.
As with any other folder icon in the Finder, Command-double-clicking on any icon in the Path Bar will open a new window to that folder.
The current folder is always displayed last in the Path Bar (even if the Path Bar is to short to display all the names), so Command-double-clicking on the last icon in the Path Bar will always open a new window to the current folder.
A user at Stack Exchange asked an interesting question recently : how can you open a new Finder window in the same folder as the frontmost window? When you open a new Finder window (Command-N in the Finder), it opens to the folder you've set in the Finder's General preferences. There may be some situations when you want to duplicate the current window, such as when you're moving files around among sub-folders in a specific folder.
Another reader, Lauri Ranta, posted a simple AppleScript, that you can use together with a keyboard shortcut, to do just this. When you run the script, it creates a new window at the same location as the frontmost window. Here's the script:
tell application "Finder"
target of window 1
make new Finder window to result
make new Finder window to home
Save this as a script, and use any tool that can apply keyboard shortcuts to AppleScripts. Or save it as an application, drag it to the Finder window toolbar, and it'll be just a click away. (You can move the application to any location you want afterwards.)
I can't find a hint for this on the site, and it's probably not new, but I only just stumbled on this. The Finder toolbar, by default, has Previous and Next buttons that let you navigate back and forth in folders. If you click the Previous button, you'll go back, one window at a time, to all the folders you've visited in that Finder window. But if you click and hold that button, you'll see a list of all the folders you've visited, and can jump to any of them by selecting one. This is a good way to get to a folder you've used but that's far from where you are in the file system.
The Accessibility pane of System Preferences holds a number of interesting adjustments you can set to make your Mac easier to use. One of them is the ability to change the size of the cursor; the pointer you see on your screen.
Go to System Preferences > Accessibility, then click on Display. Drag the Cursor Size slider from Normal (smallest) toward Large. Find the size you want to use, and close the preference pane.
I have a 27" Thunderbolt Display, and I find the normal-sized cursor a bit small, so I've set mine to be a bit larger. You may find this to be a useful tweak as well.
Note that some applications may not use the changed setting. Feel free to post in the comments any apps that don't inherit this setting.
You may know that you can enter Time Machine through the GUI and delete a backup. In some cases, under Mountain Lion, this results in an error, with a message saying "The operation can't be completed because backup items can't be modified."
In some cases, deleting backups from the Finder won't work; you also may not be able to use the rm command to delete these backups, because they are handled in a special way. Finally, even if all goes well, you may want to delete backups on a remote Mac's Time Machine disk.
There is an executable accessible from the command line that lets you delete these backups. To use this with Mountain Lion, run the following command:
You can exclude certain files and folders from your Time Machine backups from the Time Machine pane in System Preferences; you can also do this from the command line. Run this command:
sudo tmutil addexclusion [path]
where [path] is a file or folder. For example, if I want to exclude my Downloads folder from Time Machine backups, I would run the following:
sudo tmutil addexclusion ~/Downloads
The tmutil addexclusion command has an interesting property: it's sticky. When you do this, the item you exclude remains in the Time Machine exclusion list even if you move it, which is not the case when you exclude items from the Time Machine preference pane. If you use the above command with the -p flag, then it will not be sticky, and will be the same as an exclusion you add from the GUI.
[kirkmc adds: Updated to correct an error in the post. I've removed the comments that pointed out the error. Sorry!]
You can use modifier keys, together with F keys, to change volume and brightness by quarter increments. To do this, press Option-Shift-F1 or Option-Shift-F2 to change the brightness by quarter steps. For volume, press Option-Shift-F11 or Option-Shift-F12 to change by quarter steps.
[kirkmc adds: This isn't new; we have a hint about this when it returned to Mac OS X 10.7.4; it had existed prior to 10.7, but was removed in the early versions of Lion. But it seemed useful to remind readers about this, and point out that it works for both volume and brightness.]
If you wish to view files in an Open window, you can use Quick Look. Just select a file and press the space bar to view it. (This works only with those files that Quick View can display.) You can also move around and view other files using the arrow keys.
[kirkmc adds: I had assumed this would already have been on the site, but I only found this hint which offers a workaround. So I wonder when this was added to OS X.]