If you use Safari on more than one machine, you might have the same problem I had. There didn't seem to be an easy way of maintaining a consistent set of bookmarks accross multiple machines. I know .mac can use iSync to do this, but I already have an email address, and $100 seems quite a lot just to keep my bookmarks up to date. Up until Safari 1.2, you couldn't even save your bookmarks as html, so you had to merge your bookmarks by hand (see this this hint).
Now that 1.2 allows you to export your bookmarks (see this hint), I thought it would be worth writing a perl script to merge two html bookmark files together. The result is available here. I've tried to make it easy to use, but it isn't perfect. It should also cope with bookmark files from other browsers which use the Netscape bookmark format to store bookmarks.
Any suggestions would be gratefully accepted. The perl script can also be called from the command line with a filename. Please note, none of your original bookmarks will be affected, unless you delete them yourself. When you import the merged bookmarks into Safari, they will appear as an imported bookmarks folder.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040224063353596