Turns out Bill Gates' attention-getting debut on Twitter was just the prelude. The Microsoft chairman and Bill & Melinda Gates Foundation co-chair today is launching a new site, dubbed The Gates Notes, where he'll be writing about what's on his mind, posting information from his trips, and sharing excerpts from his exchanges with experts and leaders in areas including science, energy, philanthropy and other global issues.

"Since leaving my fulltime job at Microsoft to dedicate more time to our foundation, a lot of people have asked me what I'm working on. It often feels like I'm back in school, as I spend a lot of my time learning about issues I'm passionate about," he says in an introductory note. "I'm fortunate because the people I'm working with and learning from are true experts in their fields. I take a lot of notes, and often share them and my own thoughts on the subject with others through email, so I can learn from them and expand the conversation."

Gates explains that he "thought it would be interesting to share these conversations more widely with a website, in the hope of getting more people thinking and learning about the issues I think are interesting and important."

It's an interesting move that could establish more of public presence for Gates independent of Microsoft or his foundation, although clearly his technological and philanthropic interests figure largely in his thinking, and will play a big role in the site.

Gates Notes includes a section dubbed "What I'm Thinking," with topics including the crisis in Haiti and the role of innovation in addressing global warming. Other sections include "What I'm Learning," "My Travels," and "Curious Classroom," in which Gates answers questions from schoolchildren around the world.

There's also a "Conversations" section that will contain interviews and exchanges with Gates and other notable people. And Gates will take on a variety of topics in the "Infrequently Asked Questions" sections

Content is expected be added regularly, depending on the pace of Gates' writing. Commenting functions and RSS feeds are on the way, promises Larry Cohen, Gates' chief of staff.