Email

Obviously there's Gmail. I use it all the time, love it muy mucho. I'm a huge fan of the by-conversation-thread organization. I am thrilled with the integration between it and Google Calendar - if the Gmail bots see what they think could be an appointment, an option will pop up on the right-hand panel to add it to your Calendar. And you can send event notices to people from either your Inbox or your Calendar. Handy!

Sendin' out an invite.

Party on a duck? (In the sponsored links. Must be one deep-pocketed duck.)

But my favorite feature in Gmail just might be the use of labels. These work just like tags on blog posts, letting you assign individual messages to as many categories as you want. Then when you click a label (found in the left panel), all those messages are instantly available. Once I label a message, I can archive it (take it out of my inbox) and then know that it's just a click away. As you can see in the screenshot, I'm using labels to help me manage all the email regarding my wedding plans.

Chat

If you use Gmail's Contacts list, you know that you can chat with your contacts right in the Gmail window, or pop out a chat to a floating window that stays open as long as you keep the Gmail window open too. I use it all the time to talk to my friend who's teaching in Taiwan, actually.

But what you might not know is that you can use your Google login for Google Talk, a chat service that's compatible with Jabber. Which means it's also compatible with both iChat and Adium. Huzzah! (And lucky, since the Google Talk Client is only available for Windows.)

To set it up in iChat, open iChat > Preferences, click the Accounts tab, and click the plus sign in the bottom left corner to add an account. For Account Type, choose Jabber. Your Jabber ID is your full Gmail address. Password is self-explanatory I hope. For Server, enter talk.google.com, and click Add. All your Gmail contacts are right there in your buddy list. Googtastic.

Setting up Google Talk in iChat.

Setting it up in Adium is even easier. Adium > Preferences. Click the Accounts tab, then the plus sign, and select Google Talk from the pop-up menu. Then just follow the prompts, G.

And if you are rocking a Windows setup, the Google Talk Client will let you make free PC-to-PC calls.