MindMeister is a "mind mapping" tool that launched last month. If you're unfamiliar with mind mapping, it's somewhere between brainstorming and an organizational chart. If you've ever had to help plan a party or put together an outline for a project, mind mapping is one of the ways to organize and order your thoughts. MindMeister replaces legal pads and crumpled up pieces of paper with an online workspace that can be revised and manipulated. Users can create ideas and connect them to one another, or build their own hierarchies--it's essentially a giant canvas.
Users of Google Docs and Spreadsheets will feel right at home, as the tool shares similar features for versioning, autosave, and collaboration. There's also built-in Skype integration, assuming your collaborators have provided their Skype username. While there's no built-in chat, users can fire up a text or voice chat on Skype by clicking on another collaborator's name.
For users who don't feel like logging in to add a quick idea to their mind map, MindMeister has a few tools that help out. Called "Geistesblitz" (meaning "mind flash"), these tools consist of a widget for OS X and Vista, and a browser extension that installs itself as a search engine in IE and Firefox's search box. When you come across something you feel like writing down, you can just enter it in, and it will be sent to whatever mind map you've chosen as the default.
MindMeister offers two tiers of service--one free, and a paid premium version that runs about $4 per month. The premium version gives users an unlimited amount of mind maps, as well as the option to embed them on blogs and Web sites. I've embedded a sample mind map after the jump.