I just bought a Nikon D50. I have Photoshop Elements 3 for the Mac, and also Picture Perfect. Is there anyway to load the NEF files into Photoshop Elements, or do I have to buy Nikon's Capture to use that format?
You just need a plugin compatible with PS Elements 3 that will read your D50's flavor of RAW/NEF. You might check out Adobe's plugin "Camera RAW". The newest may support the D50. Otherwise checkout the Nikon's PP or View. On Windows, they ship will a PS compatible plugin, though the PP plugin is extremely poor IMHO.
Photoshop Elements 3 does read the NEF files once you update Adobe Camera Raw to its latest version. However, when you open the NEF files, PSE3 opens the images in its "best interpretation" of the image--ie the pics are not "as shot" out of the camera (except for the white balance).
To obtain images "as shot" out of the camera, I had to get Nikon Capture. I think Nikon View does this as well, but I wanted to have a little more control over the images with Capture. Once you save an image with Capture, you can still edit it in PSE3, but be sure to save as an 8 bit file as you can't use all of PSE3's capabilities on the saved 16 bit file.