#18 Web-only guest access:

The OS X Mountain Lion comes up with a web only guest account, so that others who needs to surf the web can access the guest account which will boot into safari mode only. In this mode, the browser Safari runs as an isolated version that stores nothing even after you quit.

#19 An Independent note taking tool:

A new feature to reckon with- iOS notes are no longer handled in mails. According to Apple, the new OS from now on deals notes with its server based services as users can enjoy the extra privilege of synchronizing their data’s and notes with other individual Mac clients and iOS devices using services like iCloud and IMAP and also using other server based clients.

#20 A more professional calendar:

Apple has introduced a new and improved version of their existing calendar called the iCal. Apple has added iCal as a widget so that users can easily find and review their dates and schedules for events. Along with that Apple also have separated reminders from the calendar, as for now both stands as a separate app in the OS.