There are some terrific new or improved tools in Photoshop CS3, and the one I'm going to discuss today is Photomerge. Adobe has enhanced this function considerably, and if you haven't used it for a while, it's worth a second look.
Photomerge allows you to take a handful of photographs of a subject, such as a landscape, and merge them into one image incorporating information from all of the individual shots. A common use for this technique is to create a panorama, as shown here using five separate images from Maui. But Photomerge is so smart that you're not limited to a horizontal sequence of shots; you can take just about any cluster of pictures, run them through Photomerge, and come out with an interesting photo.
You'll find this tool under the File menu: File > Automate > Photomerge. You have a number of layout options such as Perspective, Reposition Only, and Interactive, but I recommend you start with Auto to get your feet wet. Choose the series of images you want to merge and click the OK button. Photomerge will go to work and build a layered file. You can work on the individual layers if you need to fors some additional tweaking, or just flatten a copy of the file for final use. Either way, you will be amazed at how smart this improved function is in CS3.