ZeEsH

Open a terminal window – either login as administrator or run as sudo

hdiutil convert -format UDRW -o newimage.img originalimage.iso

1. Download the desired .img file
2. Open a Terminal (in /Applications/Utilities/)
3. Run diskutil list to get the current list of devices
4. Insert your flash media
5. Run diskutil list again and determine the device node assigned to your flash media (e.g. /dev/disk2)
6. Run diskutil unmountDisk /dev/diskN (replace N with the disk number from the last command; in the previous example, N would be 2)
7. Execute sudo dd if=/path/to/downloaded.img of=/dev/rdiskN bs=1m (replace /path/to/downloaded.img with the path where the image file is located; for example, ./ubuntu.img, /dev/rdiskN is faster than /dev/diskN). If you see the error dd: Invalid number `1m', you are using GNU dd. Use the same command but replace bs=1m with bs=1M.
8. Run diskutil eject /dev/diskN and remove your flash media when the command completes

There are a couple of ways to make your Mac require a password when you leave it. The easiest way is to set “Require password after sleep or screen saver begins” in the Security section of System Preferences. Here, you can also set a time limit so a password isn’t required right away, but only after 15 minutes for example.

If you would prefer a keyboard shortcut to lock the screen, you can create this yourself. Open up Automator (in the Applications folder) and choose a Service template. From the library choose “Run Shell Script” and drag it across to the workflow area. In the text box paste the following command:

‘/System/Library/CoreServices/Menu Extras/User.menu/Contents/Resources/CGSession’ -suspend

Finally, change the “text” drop-down menu above the workflow to “no input” and then save you workflow as “Lock Screen”. To add the keyboard shortcut, go to the Keyboard section of System Preferences and click the Keyboard shortcuts tab. Select Services from the list on the left, then scroll down to the bottom of the list on the right to find “Lock Screen”. Double-click on the area to the right “Lock Screen”, then press the keyboard shortcut you want. I used Command-Control-L.

My normal OS X account is not the “Administrator” account. For daily use, I want as much protection as possible so that I don’t screw up the system. However, there are times when I need Admin privileges or even root privileges. In the past, I used to logout of my user account and login to my Admin account to perform these tasks.

I’ve discovered an easier way for simple jobs. Since OS X is a true multiuser system I can be logged in more than once at the same time! I open a terminal window and from my user prompt, I type login admin_name where admin_name is the name of my Admin account. I then enter my Admin password when prompted and voila, I’m logged in as the Administrator.

From there, I can do anything I want with all of the privileges of my Admin account. And if I need temporary root privileges, I can use sudo. All the while, of course, I am still logged into the GUI with my normal user account.

When you are done in the terminal, type ‘exit’ or ‘logout’ to sequentially log out of each account that was logged in.

MKVtools – There are so many apps out there for Windows to convert video from mkv to mp4. I have a PS3 and have downloaded a HD video that has the extension mkv. Matroska (mkv) is just a container. The video file usually contained within the mkv file is encoded with h.264 which can be played back on the PS3 but the PS3 can not understand the container mkv. With MKVtools you can just extract the video and audio and put them in the mp4 container to be played back on the PS3 without rencoding the video and audio.

Read through the walkthrough on how to use MKVtools – Read