The top 25 overlooked and underrated features in Leopard

Editing PDFs in Preview

Beyond just copying and pasting text, Preview now offers light editing capabilities for PDF files. The ability to generate PDFs isn't new; it has always been built into Mac OS X, first as a print preview feature and later as a complete printing alternative. The ability to modify an existing PDF, however, has largely remained the province of desktop publishing.

Leopard introduces full PDF editing capabilities (including adding comments) to Preview, making it a great entry-level PDF management tool.

Dictionary Wikipedia searches and grammar checking

Mac OS X's systemwide dictionary has gotten a couple of subtle updates. It now offers the ability to look up phrases via Wikipedia as well as through its standard dictionary, thesaurus and Apple-related phrases dictionary. It also includes a grammar-checker in applications such as TextEdit that fully support the use of the dictionary.

Archiving mailboxes in Mail

Mail sports a number of new and well-known features such as Notes and To-Dos, RSS reader capabilities, and stationery for sending rich text messages. One lesser-known feature in Mail is the ability to archive a mailbox.

When you archive a mailbox (right- or control-click and select Archive Mailbox), its contents are saved to a pair of files that can then be stored for later use (allowing you to clear out Mail by removing the mailbox) or imported into Mail on another computer (allowing an easy way to transfer e-mail to a new machine).

Data detectors in Mail

Although most Leopard users have heard of Mail's data detectors, they generally don't get noticed that much, probably because they're seen only when you mouse over relevant data such as dates (including words like "tomorrow" or "Monday"), names of contacts, addresses or phone numbers.

When you mouse over such an item, a small selection box appears with a downward-facing triangle icon. Clicking on that icon lets you create new iCal events (without opening iCal), view a date in iCal, add an address or phone number to a new or existing contact (again without opening Address Book), view a contact or even view a location using Google Maps -- all from a single click and without any copying or pasting.

This may not be a totally hidden Leopard feature, but it's one with a lot of hidden potential.

Attachments in iCal

Much like an e-mail message, you can now attach files -- pictures, Keynote or PowerPoint presentations, Word documents or anything else -- to events in iCal. This helps ensure that you have information about events at your disposal. It's also great if you're using Leopard Server's iCal Server or sharing events with others by e-mailing the event or publishing your calendar -- files are included as part of the event, making it easy to collaborate through iCal.

Signed applications

When an application is signed, it has a digital signature embedded as part of its file structure. This signature can be used by Leopard to verify that the application was created by a legitimate developer, in much the same way that Web browsers use digital certificates verified by an online certificate authority to ensure that online banking and e-commerce sites are secure and legitimate. The signature also indicates that the application hasn't been tampered with. All Apple applications now include digital certificates, and Leopard can sign applications from other developers that lack a certificate.

So what does this mean for users? It means that Leopard can alert you if an application has been modified by a piece of malicious code without your knowledge. It also means that Leopard's built-in firewall can block or allow access to the Internet based on an application's signature, rather than just using the port number it communicates on. To use a broad example, you could allow Web traffic from Safari but not Firefox.

Digital signatures are also supported in Parental Controls in Leopard, so if you limit the applications that your children are allowed to use, even if they move or rename them, Leopard will recognize them based on their signature and deny access.