Gmail Labs have many features being tested. There are many very useful features like signature tweak, mizzle, vacation time, etc.. See the below list of currently available features. To enable in your Gmail or Google Apps for domain account, login to the mail, go to Settings –> Labs and enable or disable the features.
Signature tweaks – Places your signature before the quoted text in a reply, and removes the “–” line that appears before signatures.
Muzzle – Conserves screen real estate by hiding your friends’ status messages.
Forgotten Attachment Detector – Prevents you from accidentally sending messages without the relevant attachments. Prompts you if you mention attaching a file, but forgot to do so.
Quote selected text – Quote the text you have selected when you reply to a message. This works best if you use keyboard shortcuts.
Right-side chat – Move the chat box to the right side of the inbox.
Right-side labels – Move the labels box to the right side of the inbox.
Email Addict – Lets you take a break from email and chat by blocking the screen for fifteen minutes and making you invisible in chat.
Mark as Read Button – Tired of spending all that effort to click on the more actions menu every time you want to mark messages as read without reading them? Now just enable this lab and that is just a button click away!
Vacation Time! – Lets you specify starting and ending dates for the vacation auto responder.
Quick Links – Adds a box to the left column that gives you 1-click access to any bookmarkable URL in TECK.IN Mail. You can use it for saving frequent searches, important individual messages, and more.
Superstars – Adds additional star icons. After enabling this feature:
(1) Go to the “General” Settings page to choose which superstars you wish to use.
(2) Use either the keyboard shortcut (‘s’) or click to rotate through your selected superstars.
(3) Use the search operator “has:” to find all messages with your superstar (e.g. “has:red-bang”, “has:blue-star”). Learn the name of a superstar by hovering over its image in the “General” Settings page.
Pictures in chat – See your friends’ profile pictures when you chat with them.
Fixed width font – Adds an option to the reply dropdown menu that lets you view a message in fixed width font.
Custom keyboard shortcuts -Lets you customize keyboard shortcut mappings. Adds a new Settings tab from which you can remap keys to various actions.
Mouse gestures – Use your mouse to navigate with gestures. Hold right-click and move the mouse left to go to a previous conversation, move it right to go to the next conversation, and move up to go back to the inbox view. Works best on Windows.
Random Signature – Rotates among random quotations for your email signature.
Custom date formats – Adds options to the general settings page allowing the date and time format to be changed independent of language. For example, you can use a 24-hour clock (14:57) or show dates with the day first (31/12/07).
Old Snakey – Kick it old school with Old Snakey! Enable keyboard shortcuts and hit ‘&’ from the main page to play a game of snake.
Hide Unread Counts – Hides the unread counts for inbox, labels, etc.
Default ‘Reply to all’ – Make ‘Reply to all’ your default option for responding to emails.
Navbar drag and drop – Allows you to reorder the items in your navbar using drag and drop.
Custom Label Colors – Lets you create your own combination of colors for labels. Instead of choosing one of the standard colors from the label dropdown menu, click on Add custom colors. Pick your combination of colors, hit Apply, and enjoy.
Go to label – Enable keyboard shortcuts and hit ‘g’ then ‘l’ to display a popup for selecting a label to go to.