That is nice. The main chalenge would be to write a directory crawler, lol. Anyway, not that I need it, but really good idea! This could also give statistical information, like disk usage, amount of files of x type and y type, similar files found (like duplicated files or something), maybe search inside zip files or rar files, brainstorming, brainstorming some more, xD.
OP, how are you planing to develop this, I mean, what languages, libraries, for what system, etc?