In iCal, you can assign a URL to an event or to-do—just fill in the obviously-named URL field when creating your new event or to-do, and you’ll wind up with a link you can use to jump to that URL from within that event. But you can also create events or to-do’s that have a clickable link as their actual title.
There are a few ways to do this. You can drag a URL from your browser’s address bar directly into iCal, for instance, and iCal will create a new event with that URL as its title. When you click this event’s title in iCal, you’ll be switched to your browser and the specified URL will load. (If you use Month view, you might think it’s now impossible to edit this event, as anywhere you click seems to take you to your browser. If you switch back to iCal, though, you’ll find the event is selected and ready for editing. You can also click in any white space next to the URL in the Month view to edit it without activating the URL.)
You can also create your own hyperlinked events and to-dos; just type the URL in angle brackets as part of the item’s title. For instance, something like this: Meet with Apple <http://www.apple.com> . After you finalize the event or to-do, you’ll see that the URL portion of the title works as a clickable link, while the text outside the angle brackets does not. While you wouldn’t want to use a super-long URL for a clickable link, you might find this useful if you have Web-related events and/or to-dos. (You could always use TinyURL.com to shrink ultra-long URLs.)
Finally, here’s a use of URLs in iCal that you may never have considered: You can link to local files (nearly) as easily as you can link to a remote Web page. So if you have a document that you need to work on for a to-do, or a saved party invitation for an upcoming event, you can link to those documents directly from your iCal event. The easiest way to do this is to use pretty much any browser other than Safari (I tested Camino, Firefox, and OmniWeb) to locate your local file.
Assuming the document you wish to link to is somewhere in your user’s folder, enter this URL in your (non-Safari) browser: file:///Users/username (yes, three slashes after file ). Replace username with your user’s short username, then press Return to load the URL. The file URL points to your local machine, not the internet, so you should be looking at a page showing the content’s of your user’s home folder.
(The reason you can’t use Safari is that Safari now uses the Finder to open file:// URLs, instead of displaying a navigable directory view in the browser window.)
Now navigate into Documents, or wherever you stored your file, until you can see the file of interest on the screen. Control-click on the file and choose Copy Link Location (or Copy URL or whatever your browser calls it). Switch back to iCal, create your event or to-do, and then select the URL field and press Command-V to paste the copied URL into that field. (You can also drag-and-drop the URL from the browser’s address bar if you want a folder’s URL—you can’t get a file’s URL in the address bar, because when you click a file in your browser, the browser will probably download it.)
Once the URL is visible, click on it and choose Open URL. If you specified a file, it should open in its usual application. If you specified a folder, that folder will open in the Finder. Keeping a link to a local file with the event or to-do makes it super-simple to access the files related to that event or to-do.