Yahoo! Messenger 10

You can log in as invisible, and choose from a dozen language variants, even Thai and Chinese.

One difference from most IM clients is that offline contacts are displayed, which isn't always what you want. Note the options for SMS (mobile phone icon), phone calling, and the separate tabs for IM Contacts and social network updates. The ad at the bottom of the window is discreet enough not to be a nuisance.

You can choose from some interesting textures, but there are just eleven.

Unlike other IM clients, Yahoo only displays the contact info and action card when you click on the contact's icon. This is nice, as it won't get in your way when you're working in other windows. Note from the card you can start a video call, phone call, or SMS, in addition to starting an IM conversation.

The social network update tab is limited because you only see updates from Yahoo contacts you've mutually agreed with instead of all your social network feed. Here you can see my updates from Twitter and Last.fm.

Here's where you decide which services and users to get updates from.

It's a nice design, clearly offering video calling, voice calling, IMVironments (wallpapers), activities that come from plugins for games and more, and photo sharing.

You can use any image from your PC drive or an Avatar you create, but you can't shoot directly from your webcam or use video as you can in Windows Live Messenger.

These are animated icons with sound. They're kind of silly, but fun for some.

These are sharing plugins for games and other activities you and your buddy can enjoy together. Yahoo is the only big IM client with a robust plug-in architecture.

You can share photos even while videoconferencing. AIM lets you do this but only in separate windows.

You can see earlier conversations, but you get more options with Digsby, like a calendar to pick a date you want to see a chat on.

You can easily start a group chat and even enable voice for it.

Yahoo offers a healthy selection of public chat rooms you can join from Yahoo! Messenger. It even offers voice capability.

Yahoo Messenger is the only major IM client aside from Skype to offer calling to regular phones. During a call, you'll see this small dialog; note the advise about call quality.