[Sidetrack]

for convenience there are some format changes I'd like to make, preferably without dumping everything out of Calibre and re-importing it. Anybody had any luck with this kind of thing? :

PRC-->MOBI (where the PRC file is actually just a MOBI file)
PDB-->Various (output the actual file the pdb contains)
TXT,RTF-->ZIP,RAR,TXTZ (convert uncompressed into compressed format)

I've specifically been trying reduce the size of my library by compressing text files TXT-->TXTZ in batch, but this results in formatting issues and needs to babysat on a per file basis. I'd be just as happy with TXT-->ZIP.

Conversion seems to engage file parsing so that it actually goes TXT-->HTML-->TXTZ and does annoying little things liking mashing together snippets of quoted verse/poetry. It seems like there are a few "conversions" of this nature that could skip the parsing process safely.