Large printed panoramic images are amazing. The days of spending hours manually blending and combing your photos are over. Photomerge is a powerful tool available in Photoshop CS4 that will do just as advertised, merge your photos together in a matter of seconds. This tutorial posted by Jay Kinhorn on Layers Magazine gives a great overview on how to use the action and get the best result. I really like his tip about zooming in and making sure your seams do not have any soft spots or aberrations, those are very apparent when printed large.
In the new CS4, there are some minor improvements to the Photomerge function, including the new collage option. Jay Kinghorn goes over the different ways of bringing your images into photomerge, the layout options, and some quick tips for creating better quality panoramas.