I'd scanned a number of pages into JPEGs from a book, and was going crazy printing image by image in Preview. Heck, even Windows lets you right-click selected files in its "Finder-equivalent" and choose Print. I had to be missing something.
Sure enough, I was. To print multiple files at once in OS X land, just open up Terminal, navigate to the directory with your images, and use the lpr command, using a space between file names!
lpr img023.jpg img024.jpg img025.jpg img026.jpg
Couldn't be easier. Even scaled each jpeg to an 8.5"x11" sheet for me. Thanks heavens.
[robg adds: If you'd like to skip the Terminal, here's the Finder solution: just drag and drop the group of images to be printed onto one of the printer icons in your user's ~/Library/Printers folder. You can even drag a printer from here to the dock (or alias it on the desktop) for fast permanent access -- this is basically what the "desktop printers" feature in 10.3 does...]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20050107155355621