Among the many ways to display trees, degree of interest (DOI) trees strike me as one potentially useful way to display trees such as the NCBI taxonomy. For background see, e.g. doi:10.1145/1133265.1133358 (or Google "degree of interest trees").
The thing that would make this really useful is if an application was written that, like Google Earth, supported a simple annotation file format. Hence, users could create their own annotation files (e.g., taxa of a certain size, those with eyes, etc.) and upload those files, creating their own annotation layers, in much the same way as we can load sets of geographical annotations into Google Earth. I think it's this feature which makes Google Earth what it is, so my question is whether we can replicate this for classifications/phylogeny?