Mail - Contacts - Task List - Calendar
You can use Google Mail, Contacts, the Task List and set up private and shared calendars.
All of these work well together.
Google+ allows you to set up different Circles of friends, such as professional, family, and people related to your hobby or special interests.
You can post things to different Circles similar to posting on your FaceBook wall.
You can also set up a Google+ Hangout which is very similar to Skype.
It is an easy process to import all your contact information from Outlook, Outlook Express, Yahoo!, HotMail, as well as the Apple Address book.