I guess there are tabs that are open through clicking a link so they'd be connected directly as a directed graph. New tabs not opened by clicking a link would appear near the others as they were opened during the same time period. I am not sure if anything of that would help but I am curious to know if anyone had explored this already.

Other stuff that comes to mind: - easy deletion of irrelevant nodes (opening a news site during a pause) - visualizing time spent on a website by node size - search (it'd be cool if the whole thing also archived or made snapshots of the visited sites, maybe just using the internet archive) - eventually tags or colors for further classification