I learned this trick when I misplaced the Leopard DVD that comes with the Macbook Pro. This time, I tried (with assurance from other blog/forum posts that it actually works – there are probably tons of more detailed tutorials than this.) doing the same for Snow Leopard.

What you need:
- External Hard Drive (USB or Firewire) –
WARNING: should not contain important files, since we will format this.
- Snow Leopard installer DVD or DMG file

Application to Use:
Disk Utility

Steps:
0. Create DMG file
Select the DVD drive from the Left Pane of Disk Utility. Then click “New Image” icon from the Top Menu. Type the filename of your choice (or retain as Mac OS X Server Install Disc) and the select destination folder and SAVE.

1. GUID Partition Table
This option allows the disk to be used to start up an Intel-based Mac.

a. Select the device (external hard drive) that will be used to boot the installer.
b. From the tab options in the Middle Pane, click “Partition”
c. Select the number of partitions you want from the Volume Scheme.

Note: Just make sure there is enough space on the partition that will be used as your “dvd” (sort of)

d. Select Options at the bottom of the Volume Scheme, then select “GUID Partition Table.” It’s hard to miss since it’s the topmost option.
e. Clicking OK will reformat the drive and create the GUID partition.

2. Restore image to the drive/partition.

a. Select your GUID partition.
b. On the Middle Pane again, select the “Restore” Tab.
c. Select a Source disk image (see Step 0).
d. Click Restore.

3. Run the installer

a. (Option 1) Mount the disk image. Go to Finder. Double click the installer to run.
b. (Option 2) Reboot. Press the letter “C” to boot from the drive or choose the boot option.

That’s it!

—–

UPDATE:

If you encounter the ff. error when restoring:

“Could not find any scan information. The source image needs to be imagescanned before it can be restored.”

Click the image to restore. Then from the menu, select Images -> Scan Image for Restore.