If you have multiple conversations visible in Messages, you can cycle through them using a keyboard shortcut: press Control-Tab to cycle down, and Shift-Control-Tab to cycle up.
There seem to be some inconsistencies. When testing this, if I had my cursor in the text field, sometimes the keyboard shortcut wouldn't work and would instead highlight the name in the To section above the conversation.
After installing Mountain Lion, I was looking for an easy way to convert the e-mails I receive into reminders to act on later. After trying in vain in Mail (right clicks, menus, etc.) I found the solution is simple.
Just drag an e-mail from Mail to Reminders and a new Reminder is automatically created with the subject of the e-mail as title and a link to the e-mail in the notes.
[kirkmc adds: To be honest, I expected there to be a clearer way to do this: a toolbar button in Mail, or a contextual menu item. I think a lot of people - like me - use their inbox as a to-do list. Being able to add them to the Reminders app can be very useful.]
Apple removed the default font settings preferences in Safari 6, but one can easily change them with a set of Terminal commands. More fun, though, is using TextExpander's Shell Script Snippet feature to do it. Slight advantage: once the snippet is in your collection, you can edit the snippet to change the fonts at any time without having to dig up the commands from your memory. Note that you have to quit and restart Safari for the changes to take effect.
Update: The submitter, Michael Cohen, wrote me saying that his brother Norman Cohen improved on the above script. I'll leave the original there, but below is a newer version, where the script quits and restarts Safari, and using TextExpander's fill-ins, lets you specify the fonts and sizes on the fly:
Since Mountain Lion was released, I find that my Macs go to sleep when I don't want them to. I had my Energy Saver preferences set to 15 minutes, but I've noticed that when something is active, such as a download, they got to sleep after 15 minutes, rather than continue with the download. This is not only incorrect behavior, but it's very annoying. What's worse, when I changed the setting to Never, they would still go to sleep during long downloads.
The Ask Different blog pointed out that there is a new command in Mountain Lion called caffeinate. This keeps the system awake, or, as the man page says, "prevent the system from sleeping on behalf of a utility."
Run it as follows in Terminal:
caffeinate -u -t 3600
3600 in the above command is the number of seconds to keep the system awake. What's interesting is that you can effectively set your Mac to shut down at a specific time (that is, the built-in sleep mechanism will start counting when that time runs out). You can also run the command alone to keep your Mac awake until you stop it by pressing Control-C.
So Mountain Lion has been out for a week, and a lot of people who read this site have developer accounts and have been using it for longer than that. What do you think of it? The best version of OS X ever? Needs more work? A total failure?
For this poll, you get to play teacher and give Mountain Lion a grade. Pass or fail? Vote here.
OS X uses a framework called launchd for "starting, stopping and managing daemons, applications, processes, and scripts." (Quote from Wikipedia.) You can use launchd to schedule any task you want to run at specific times or intervals.
Nathan Grigg has posted a simple, clear tutorial, Schedule jobs using launchd which gives an introduction into how this process works, and how you can use it to schedule repeated tasks on your Mac. You'll have to edit plist files, and you may want to install some third-party tools, but this can be useful if you want to set up your own tasks. You could use cron, but, as Grigg says, "Unlike cron, launchd does not assume that your computer is always running. So if your computer happens to be sleeping at the time a job is scheduled, it will run the job when it wakes up."
In Safari 6, and Mountain Lion, you can use a two-finger pinch to view and switch tabs.
Once you pinch in Safari (assuming multiple tabs are opened) you will get a view similar to that of Safari on iOS, and you can navigate among tabs using two-finger swipes to the right and left, arrow keys or a mouse or trackpad. This is an interesting way to preview all open tabs without having to load them fully.
You can either press Return, click the mouse or tap to select the frontmost tab, or pinch out to stay where you are. You can also close any tabs by clicking the close button in their headers or pressing Command-W while in this view.
[kirkmc adds: Interesting idea. I find all these gestures a bit hard to remember, but this one may actually become instinctive over time. Personally, I'll stick with Command-Shift-arrow key to cycle through tabs… Following the comments below, I've changed the category to 10.8. I had expected this to work across the board in Safari 6.]
By default Gatekeeper allows you to run apps from the Mac App Store and from verified developers. You can change this setting in the Security preference pane. If you use this setting, or the Mac App Store only setting, you can still run unsigned apps. Just Control- or right-click on an app and choose Open. Gatekeeper will display a dialog asking if you're sure you want to open the application.
[kirkmc adds: There is an extensive article on Macworld about Gatekeeper, but I felt this would be good to mention as a hint. I think most readers of this site won't use the restrictive settings, but you may work with others who do, or administer computers, and may want to launch unapproved apps on those computers from time to time.]
I was rooting around my system today, and wondering if there's any way to find out if an application is from the Mac App Store. The Info window - when you select an item and press Command-I - doesn't say anything, but the System Information application does. There is an "App Store" column which says yes or no for each application.
I figured there had to be another way, and eventually found that the mdls command gives some of this information. Running mdls <app name> returns a lot of information, but near the top of the list are a few lines like this:
The kMDItemAppStoreHasReceipt is what says whether or not it is a Mac App Store application, but you can see some other Mac App Store information there, such as the category (non-MAS apps have this too, interestingly), the purchase date, the application's ID, etc.
My interest in this is purely academic, but it could be useful to find all Mac App Store applications on a given Mac; you could use the kMDItemAppStoreHasReceipt key in a search, for example. If you run this in Terminal, you'll get a list of all your Mac App Store applications:
Note that if you have any volumes excluded from Spotlight searches, their Mac App Store apps won't be listed in the results. (H/t to Thomas for that command.)
If anyone has any other ways of finding this information, feel free to post them in the comments.