One of the often overlooked features of Safari is its Activity window, hiding in plain sight in the Window menu (or just press Command-Option-A for fast access). The Activity window shows, as you might have guessed by now, activity related to the Web pages you are viewing. If you try to load a page and it stalls out with “loading,” for instance, the Activity window will show you exactly which item is causing the problem—just click the disclosure triangle next to the page in question, and you’ll see entries for every item on the page, and (if those items are loaded) their size or (if they’re not loaded) a message showing their status.
But there are more interesting things you can do with the Activity window. Are you an aspiring Web site designer, trying to learn more about CSS or JavaScript programming? One of the best ways to learn about such things is by looking at examples from other sites. Typically, that involves opening the site, viewing the source code, scanning for the CSS and JavaScript URLs, copying them, opening a new window, and then pasting the copied URL. Using Safari’s Activity window, it’s much simpler: click the disclosure triangle for the site you’re viewing, scan the list of objects for the .css or .js files, then double-click—the selected file will open in Safari.
You can use this same technique to view embedded Flash or QuickTime movies in their own windows—just find the .flv, .wmv, or .mov files in the list in the Activity window, and double-click.
Want to download something that’s on the page? Or a bunch of somethings? Just Option-double-click on any element in the window, and it will then show up in Safari’s Downloads window, and start downloading. Want to download a bunch of stuff? Make your selection (using Command-A for all, or a combination of Shift and Command clicking for subsets), press Command-C to copy the entries, switch to the Downloads window, and then press Command-V to paste the list. Bingo, everything you copied will start downloading.
But perhaps one of the neatest tricks with the Downloads window is to quickly create a set of bookmarks for your currently-open tabs. Safari in OS X 10.4 lacks a “create bookmarks folder from these tabs” feature, but the Activity window provides a workable solution. Yes, you could also install SafariStand, a Safari plug-in that provides this, and many other features. But if you’d rather not install any Safari plug-ins, try this instead.
Open the sites you wish to bookmark, each in its own tab, then open the Activity window. Leave all the disclosure triangles closed, so that all you see is the name of each site, like this:

Now press Command-A to select all and Command-C to copy the selection. Press Command-Option-B to open the Bookmarks window, and then navigate to the spot where you’d like to store your new bookmark collection. Create a new folder (if you wish) at that location by clicking the plus sign at the bottom of the window (the one on the right, under the Bookmark section). With the new folder still selected, press Command-V to paste the clipboard contents. That’s it—you’ve created a folder of bookmarks based on the currently loaded tab set. While not quite as simple as selecting a menu item in Firefox (Bookmark All Tabs), it’s not bad as workarounds go.