How do I keep my Safari bookmarks in sync?

Safari bookmarks are stored in your ~/Library/Safari folder, so at it's most basic, you can easily copy the bookmarks file from machine to machine.

The format of this file is kinda funky, it's not a simple HTML-based file as with most other Web browsers, but rather a hard-to-read XML datafile that is faster for programs to parse, but pretty much impossible for us wetware to eyeball.

In this instance, I'm going to assume that the machines are networked and that the remote system is called "Laptop" and that it's already connected.

$ cd ~/Library/Safari
$ cp Bookmarks.plist \
/Volumes/Laptop/Users/taylor/Library/Safari
$ cd

If you can't get the two to network because they're in different locations, you can easily email the bookmarks.plist file to yourself then retreive it on the remote system, or upload it to a central backup disk or server (that is, something like .Mac or a Web server).

Digging around a bit, Firefox has a really weird way of storing its bookmarks too (even though it's ostensibly an HTML file) so automatically syncing the two with some code looks pretty tough. The Firefox bookmarks are stored, on my system, in /Users/taylor/Library/Application Support/Firefox/Profiles/6j6l7kgv.default/bookmarks.html, but if that weird directory path isn't enough to make you say "hmmmm...." then check out the first few lines of the file itself:

$ head bookmarks.html
<!DOCTYPE NETSCAPE-Bookmark-file-1>
<!-- This is an automatically generated file.
     It will be read and overwritten.
     DO NOT EDIT! -->
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8">
<TITLE>Bookmarks</TITLE>
<H1 LAST_MODIFIED="1103387323">Bookmarks</H1>

<DL><p>
    <DT><H3 PERSONAL_TOOLBAR_FOLDER="true" ID="rdf:#$FvPhC3">Bookmarks Toolbar Folder</H3>