visualizing hierarchical data

I'm looking for techniques for displaying hierarchical data.

I find my experience is, unf开发者_C百科ortunately limited to how Windows presents hierarchies:

1) TreeView - vertical expansion (as in file explorer, and Windows 7 start menu)

2) Start menus - largely horizontal expansion (XP style)

I'm looking for new/fresh ways to visualize hierarchical data to the user however. Looking for studies, can be academic, still searching. I'm currently browsing through Hierarchical Data Visualization In Desktop Virtual Reality, which is quite cool, looking for more input.

Some ideas and examples of how to display hierarchical data are discussed in the following two questions:

• "What's the best way to view a deep hierarchy?"
• "Alternatives for Tree structure"