How can I burn a Raspberry Pi image to SD card from Ubuntu?

You can do it from the command line as well. No need to install anything.

1. Find the name of the device of the plugged in SD-card. For instance I typed ls -la /dev/sd* before and after plugging in the sd-card. I saw the date of /dev/sdc change and thus decided that that was the one.

2. Find the place of the unzipped image, which was /home/username/Downloads/2012-10-28-wheezy-raspbian.img for me.

Type the following (mutatis mutandis):

sudo dd if=/home/username/Downloads/2012-10-28-wheezy-raspbian.img of=/dev/sdc

or with improvements suggested by other users:

sudo dd if=/home/username/Downloads/2012-10-28-wheezy-raspbian.img of=/dev/sdc status=progress bs=4M

and wait for the command to return. It may be quite a while, especially over usb2.

Resizing can be done from the Pi itself in the raspi-config program that starts automatically the first time you boot.

Be careful. Make absolutely sure the device name is that of the SD-card. If you replace it with the device name of your hard drive, your hard drive will be overwritten.

On Ubuntu versions 14.04, 16.04 and 18.04, right click on the installer image and choose Open with disk images writer. Select your SD card unit and press Start.

Easy Install & Resize the SD Card on the Raspberry Pi on Ubuntu.

1. First, open a terminal and install the ImageWriter and GParted utilities with apt-get:

   sudo apt-get install usb-imagewriter gparted
   

2. Assuming you are starting with a fresh install, download the newest release from the Raspberry Pi download site.

3. Extract the downloaded archive, and then open ImageWriter by typping in a console:

   sudo imagewriter
   

4. Select the desired .img file and target device, in this case, debian6-19-04-2012.img, and /dev/mmcblk0

   

5. Once the image write has completed, the next task is to repartition the SD card. Note: this process can be done at any later as well, it is not limited to only during initial setup!

For 13.04 you can find packages here.

If you're interested on resizing your SD CARD, check the source of this answer

Source

On 13.10 I couldn't get usb-imagewriter to install E: Unable to locate package usb-imagewriter.

I found that plain old gnome-disks command Disks from desktop worked. You can select the usb drive and have the option to Restore disk image.

Use Startup Disk Creator. It should be installed on Ubuntu by default. It worked for me very well.