Lingr is a really slick chat service that launched late last year. Lingr lets you create and manage Web chatrooms, combined with some handy technologies to help you keep track of conversations, even when you're not there.
I recently broke down a few of the top apps for chatting, both Web based and software downloads, but Lingr is a straight up chat destination as opposed to a piggy-backing service. Lingr lets you create your own tags for a chat room to make it easily searchable by others. These tags show up in a tag cloud on the front door of Lingr.com, and grow with size based on popularity. Clicking any of these tags will pull down a listing of rooms that contain that tag. It feels a little bit like Flickr.
Each chat room is pretty straightforward with a user list and a chat area. Room owners can even upload their own graphic to brand the room. Everything written is automatically archived, and can be seen by everyone, which is a little more obtrusive than some other casual Web chat apps (like Yaplet which only keeps 20 lines of chat), but if you're used to Gmail-like back-up, Lingr has you covered.
If you want to keep track of live conversations without keeping an open Lingr window, you can use Lingr Radar, which is a small (~400k) download for Mac OSX and Windows. Radar sits on your taskbar (or command bar on a Mac) and pops up with live messages for whatever chat rooms you've set up to track. It's pretty much like an RSS feed for chatrooms. I wouldn't use this, but it's nice for people who want to keep an eye on a conversation while doing something else on their computer.
To share a Lingr room with others, you can create a Lingr badge. Each badge shows basic room information like the room name, and how many people are currently in the room. Clicking the link takes you straight to the room (see embed below). You can also use your own CSS to match the look and the feel of the badge with your Web site. This is great for blogs.
Lingr is a simple solution for Web chat. I like that it doesn't take over your browser window with a sidebar, and the archiving functions are pretty handy if you're into logging things, or catching up on what's going on in a conversation. I'd like to see some skinning options to customize the look and feel of rooms a little bit, but as it stands it's no frills visual style is clean and useful.