This is a really good time to be into design for lots of exciting things are happening.
Mozilla have introduced a concept series' call for participation. This wants ideas and concepts from anybody. I have a few ideas about browsers that were similar to Aza Raskin's ideas (though his are targetted more at mobile devices whereas mine are closer to the desktop) though I want to handle history more differently. I hope to have a brief demo up soon which I will have on this site.
My major interest is in navigation. It's a personal interest for I often forget where I've been or where exactly is a piece of interesting information that I came across earlier today, yesterday, last week or whatever. The current system of bookmarks and history is workable, but I don't think it's the best solution - it rather stems from being the solution that was easiest to program and is now an established convention. A replacement would have to be very good to succeed, but it is possible. A set of different ideas can also be seen from Wei Zhou.
Watch this space...