imo.im has many features for its instant messaging users. Some highlights include:
Favorite Buddies Tag and easily reference the buddies you chat with most.
Buddy Icons View and upload buddy icons directly in imo.
Buddy Search Quickly search through your online and offline buddies.
Buddy Aliases Change how a buddy’s display name appears in the contact list
Buddy List Organization Organize your buddy list by dragging and dropping your buddies into the groups you want.
Blocking and Invisibility Blocking and invisibility capabilities, as well as the ability to specify whether your want to let non-buddies im you, no matter what client you use.
Keyboard Shortcuts Access common commands with your keyboard.
Voice Chat Hold voice chats with any of your buddies, no matter what client they use. No downloads are necessary.
Video Chat Hold web-based video chats with any of your buddies, no matter what client they use. No downloads are necessary.
Linked Accounts If you sign into more than one account you can link your accounts. When you link your accounts, logging into any one of your linked accounts will automatically sign you into the other accounts.
Pop-out mode This mode lets you IM and surf the web at the same time. When you enter pop-out mode, a new window containing imo.im will pop-up to the side. This pop-out window will be a tabbed version of the imo.im user interface. Your original window will be resized and your home page will be loaded into it.