Filtering is an essential Gmail power-user feature. With filters (and labels) you can use Gmail to handle a ton of incoming mail. I know — I’m subscribed to 64 mailing lists at Google. My filters let me manage the deluge with ease.

But managing the filters themselves has been another story. Each filter has to be crafted individually — though the ability to "filter messages like these" (see "More actions" while reading a message) does simplify the most common case a great deal.
Filter import/export, available today in Gmail Labs, helps you work with filters in bulk, rather than just one at a time. The basic function is simple: turn it on from the Labs tab under Settings, and from the Settings > Filters page you can download a file containing some or all of your filters or upload a file to create a set of filters all in one go.
Here are some other ideas for things you can do by importing and/or exporting your filters:

• Download all your filters. If you’re using POP or IMAP to get backup copies of your mail messages, now you can include your filters too.
• Share filters with other people. If you have a set of filters that is especially good at organizing particular kinds of mail that others also receive, you can now make those filters available to them.
• Temporarily "disable" a set of filters by exporting them and then deleting them. To "reenable" them, just re-import them from the file you exported.
• If you’re comfortable editing XML, you can make new filters that are similar to existing filters. Export the old ones, edit the resulting XML file, and import it back again. For more information about modifying these XML files, see Gmail Labs user group for Filter import/export.

via Gmail

There are added two new features in Gmail. Task and Text Messaging in Chat.

Tasks
Keep track of what you need to do with a lightweight task list right inside of Gmail. Just click and type to add new tasks, convert emails into tasks, and (most satisfyingly) check them off as you’re done. Once you turn on this Labs feature, look for the Tasks link to the left of your inbox under Contacts.

Text Messaging in Chat
Send SMS text messages right from Gmail. You chat from your comfy computer and reach your friends on the go; they get your messages as texts and can peck out replies on their little keyboards.

You can add this two features by sign-in to you Gmail account and after settings. Find Labs tab and activate Tasks of Text Messaging. In the Labs you can find a lot of other options that can be added to Gmail account.