Use a set-based filesystem (instead of directory based). These would act like tags. Sets generated from predicates would also be handled by the filesystem (when used), for example
?size<1M. These could also include file extensions.
for files in the set 'media' which were modified since yesterday, and
for the most recently modified file (by the user). Perhaps don't use '>' since bash will not like it.
Give programs only restrictive access - just because I started firefox doesn't mean I want it to have write access to all of my files
Check-word for repositories, separated by a '#' symbol (usage optional). This is compatible with URLs
Good ideas that people should do