If you are looking to save time as you work a shoot, before you start developing it think ahead about which images are shot under similar conditions and therefore need similar adjustments, or which images you  you want similar treatments for (e.g. black and white), and apply your changes to these groups of images all at once.

Lightroom is a relatively new program, but there are already multiple ways of accomplishing this,  each with a different twist.   You have three main choices:

1.  Make changes to your first image and then synchronize the settings:

• After making the changes to the first image, in the filmstrip select all of the images you want to apply the setting to, including the one you already did.
• Make sure the one you already did is “active”.  Do this by clicking inside the thumbnail for that image, so that the border is brighter than the other selected images.  (Clicking outside the thumbnail will break apart the selection!)
• Click on the Sync… button at the bottom of the right-hand panel strip. (If you don’t have multiple images selected, you won’t see it.)
• Choose which settings from the active image you want to apply to the rest of the images, and hit Synchronize.

2.  Make changes to all of the images at once:

• In the filmstrip, select all of the images you want to affect.   Decide which of these images you want to see as you work, and click inside its thumbnail to make it active.
• Hold down the Ctl/Cmd key, and click on the Sync… button to change it to Auto Sync.  (Lightroom 3 Update:  Click on the switch to the left of the Sync button!)
• With Auto Sync on, make changes to the active image.  Notice how the same changes are applied to all of the selected images automatically.
• Remember to turn Auto Sync off, or you may end up making unintended changes to groups of images.  Hold down the Ctl/Cmd key and click on Auto Sync to change it back to Sync…  (Lightroom 3 Update:  Click on the switch to the left of the Sync button.)

3.  Copy and Paste your settings:

This method works for applying settings to one additional image, not groups of images.  I find it completely unnecessary given the Sync functionality, but since the buttons are there (at the bottom of the left hand panel strip), I will mention it.

• Make changes to your first image.
• Hit Copy, and select which settings you want to copy to another image.
• Select another image you want to apply the settings to.
• Hit Paste.

Figure out which method(s) you prefer, get in the habit of using them, and really start to leverage the power of Lightroom to get you away from the computer in much less time.