A friend and I were surprised to discover that Safari knows how to display Photoshop .PSD files! It opens both local and remotely served .PSD files as easily as a .JPG or other supported image file formats. In retrospect, this ability may be due to a shared system-wide library in OSX rather than Safari itself, as the Finder image preview (in column mode) and Preview.app also have this ability (similar to how Safari will also open and display .rtf files).

Related hints:

Print Photoshop files through Preview
Use Preview on Photoshop files

I found an interesting Safari bookmarks page on Apple's site. On this page, they provide some useful JavaScript bookmarks that can communicate with additional applications such as Sherloc.

Here's an alternative version to search webster for a word definition. Enter the following bookmark defintion as one line with no spaces at all between characters:

javascript:x=escape(getSelection());window.location=
  'http://www.webster.com/cgi-bin/dictionary?book=dictionary&va='+x;

[robg adds: The submitted hint also included a JavaScript to search Google for the selected text, but it's somewhat redundant -- you can just control-click on any selected text and choose Google search. However, for completeness sake, here's the Google JavaScript:

javascript:x=escape(getSelection());window.location=
  'http://www.google.com/search?q='+x;

Again, enter it as one line without any spaces at all.]

Mozilla is nice because if you want to save an embedded movie or flash file from a website, it had a Site Info viewer to you could see all of the files associated with a website.

Though Safari lacks an exact duplicate for this feature, if you open the Activity Window in Safari, you can just double click any part of it and it will open in a Safari window. You can then do a 'Save As' and you get the flash movie (or whatever) saved locally.

You may have known this already, but it's new to me and sure beats 'View Source' and copying information.

[robg adds: If you haven't used the Activity window in Safari, you're missing out on one of its nicer features, in my opinion. You can easily see the various bits that are used to create each page, and as noted here, open any one of them easily with a double-click. I use this window all the time to load CSS and JavaScript source files.]

Since the release of Safari I've been waiting for a way to go back into my download history and find the URL from my downloads and to my surprise I've found that Safari does store that info but doesn't give you a way to view it through the GUI!

Open this file:

~/Library/Safari/Downloads.plist

in any text editor (or I perfer Apple's Plist Editor from the Developer Tools), and you will see a list of each download along with the URL it came from and its size (in bytes).

One thing that annoys me about Safari is that it stores internet site's favicons. These files quickly add up to MBs of space. That's bad if you use Apple's Backup software to up backup Safari to your iDisk. But there's a quick-fix. Go to Users -> username -> Library -> Safari.

Go into the Icons folder and delete everything in there. Once you have deleted everything, return to the Safari folder and click on (highlighting) the Icons folder. Get Info and click the triangle next to Ownership & Permissions. Change the Owner to you (your short Unix name) and set the access to "Read only" then set the rest of the access lines to "No access"

Now when you surf the net, you'll find that Safari displays the icons, but when you quit and restart Safari all of those icons are gone. Your iDisk will love you in the morning!

If you want to change the email client that Mozilla launches when an email link ("mailto" link) is clicked then:

1. Launch Mozilla and enter the URL about:config and hit Enter.
2. Control-click (or right-click) on any list entry and choose the New pop-up menu, and then the String sub-menu. In the first pop-up that appears, put applications.mailto. In the second, put (for example), the path to the OS X Mail application:
   file:///Applications/Mail.app/Contents/MacOS/Mail
3. Control-click on any entry, and again select New and String. Put applications.mailto.parameters in the first pop-up, then put "%url%" in the second pop-up.
4. Control-click on any entry, but this time select New and then Boolean. Enter network.protocol-handler.external.mailto in the first pop-up, and then put true in the second.

Restart Mozilla and send Steve Jobs an email to test it out!

[robg adds: A previous hint covered this in a slightly different manner; I think this new hint is a bit clearer on the whole process.]

Most of you may know already that the final version of Safari introduces Auto-Tabs. An Auto-Tab is a folder of bookmarks that behaves as one bookmark -- when clicked, it will open all the URLs in the folder in separate tabs. To enable Auto-Tabs for a folder, open the Bookmark view and then find the folder you'd like to modify, and then just check the Auto-Tabs box. Once checked, the little triangle in the folder's name will become a little square, and now your folder acts like a single URL bookmark. Quite handy.

But what if you want to access just one of the URLs in your new auto-tabbed folder? To bring back the dropdown menu, just press Option key before you click on the auto-tabbed folder; you'll get the standard dropdown list of all the URLs in the folder.

[robg adds: I found that the Command key also works to display the dropdown menu.]

I felt that the default text sizes in Safari were too large for my liking, but reducing them in the Prefs resulted in quite a few sites showing small, unreadable, and non antialiased fonts in places. In an attempt to fix this, I looked into the preferences for OmniWeb and copied the following lines into Safari's plist (~/Library -> Preferences -> com.apple.Safari.plist):

        <key>AppleAntiAliasingThreshold</key>
        <integer>2</integer>
        <key>AppleScreenAdvanceSizeThreshold</key>
        <integer>2</integer>
        <key>AppleSmoothFontsSizeThreshold</key>
        <integer>2</integer>

This appears to have fixed the problem, forcing all fonts to be antialiased (I know some people don't like it, but I do!). They may not all be necessary, but I haven't tested them one-by-one to see.

I like to keep Safari's bookmark bar organized so I can get places quicker. So I use dividers to separate my folders, JavaScript search buttons, and single page bookmarks.

Click on the bookmark icon to show all bookmarks, and duplicate a bookmark you use a lot (in my case, a search Froogle javascript). Rename it "||" or something else divisive, and drag it in-between your different types of bookmark buttons. Voila! Topically separated bookmarks.

Also, I like to indicate search JavaScripts with a "»" suffix just to remind myself what they'll do.

[robg adds: I had done this for a while, but found that I preferred having the Command-1 through Command-9 shortcuts (for the first nine items on the bookmarks bar) functional instead. With dividers, you'll give up some keyboard shortcuts, but it may be worth it if you're primarily a mouse user...]

I like having the Address bar hidden in Safari. This saves space. When the address bar is hidden, you can press Command-L to show it and enter any URL, and when you press Return to confirm it, the Address Bar automagically slides away.

Furthermore, when you open new tabs/windows, you can enter URLs even though the Address Bar is hidden. This might be considered a bug, though.

[robg adds: How very odd -- you can, indeed, enter URLs with an invisible address bar on a new tab or window!]