Recently I've had to print a lot of pictures in .PSD format through Photoshop. I had to do multiple copies and got pretty annoyed at the time it takes to spool the jobs. So I just tried it with Preview instead, and it worked great!
On our HP 8500N, printing multiple pages through Photoshop sent the job every time for each page, not good for a 50Mb file. Print the same file trough Preview and it just sends a copy command to the printer, so it only sends the spooled file once and tells the printer to make X copies. Much quicker and, if my eyes aren't failing, slightly better print quality too which is weird.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20021112052251922