Renaming Tab and Field Labels

Customise >>  Tab names and labels.

 Note: To change the name of field, do click on button 'Next' once you get an option to change the label of the tab. This usually gets missed and it seems that the link is only for changing the tab names.

Some useful SF links:
Renaming Tab and Field Labels
Considerations for renaming tabs and field labels

Smarter "Out of Office"

I was asked if there is a way to use "out of office" in such a way that if someone assigns a task to somebody who is "out of office", SF can assign the task to someone else.

As of Nov 2013, this cannot be done using the standard SF functionality. The idea has been put forward in various forums various times. However, this can be achieved with the help of some coding, leveraging the calendar object in Apex.

Setting "Out of Office" in Salesforce Calendar

Availability status is part of an "event" added to a calendar and not visible by default. To make it visible, the System Administrator needs to first add the field "Show Time As" to the page layout. This can be done as follows:

1. Click on: Setup >> App Setup >> Customize >> Activities >> Event Page Layouts. 
2. Edit the page layout. 
3. Click and drag the "Show Time As" field into the page layout into "Calendar Details" section

 You can now change the availability status to "Out of Office", "Busy", or "Available" when you add an event to the SFDC calendar.