Cool Gmail Lab features that you should enable

Here are some Gmail Lab features that have become a part of my Gmail now. Not that they are must-have features, but they do make life easier than it would be otherwise. And there is no particular order in the list here.

1. Mark as Read Button
   
   
   
   
   
   There are so many mails that you don't want to open. Like notifications from facebook/gmail/twitter. The subject line itself gives you enough information that you will prefer to make it as read. Instead of selecting it from drop down menu, a "Mark as Read" Button just next to "Delete button" comes handy. Enable this features to have "Mark as Read Button".
2. Google Docs preview in main
   
   
   
   
   
   With so many office documents moving around in mails, I use Google Docs - an online Document editor. With this feature enabled, you can view your attached documents in Google Docs without having to download it to the system.
   
3. Custom Keyboard Shortcuts
   
   
   
   
   
   You can browser your Gmail using your keyboard with this feature enabled. It lets you define various actions for various keys. Like reading mails, composing them, making it archive and many more.
   
4. Inbox Preview
   
   
   
   
   
   This is one of the best feature I loved. This features enables you to see a preview of first few mails of your inbox right when your inbox is still loading. And you can sign out if you wish to without having to completely log in to the inbox. Try this once.
   
5. Add any Gadget by URL
   
   
   
   
   
   This features lets you add many more gadgets to your inbox. You can add all the iGoogle Gadgets. This adds a new item in your settings from where you can add other gadgets.
6. Old Snakey
   
   
   
   
   
   Not something really productive for your business or mailing work, it's just the Old Snakey Game. This game to a kid is like "Hello, World!" code for a programmer. A Bonus. Didn't want to include it in this list but I still have some childhood love for it.
   
   

There are many more features to experiment at Lab. Try them all. :)