On my Kodak MC3 digital camera/MP3 player, when copying files to it's music folder on the compactflash card via the finder, it creates "._filename" files that cause the camera to freeze for long periods of time when it encounters them. I found there was no way to delete them in X. However, after fooling around a bit in the Terminal, I found that using the 'mv' and 'cp' commands will move or copy files to the compactflash card without the ._ files.
And of course, if you don't like the terminal, an applescript studio app could be made relatively simple to copy these files with the cp or mv function, which is what I did to solve my own issue.
[Editor's note: For the newcomers to OS X, it's very important to note that if you wish to retain your resource fork information, you should NOT use this method of copying files from the Terminal! But it can be useful when transferring files to systems that don't understand resource forks.]

