Mac and Windows CLI tricks
Make Apple Mail.app faster
sqlite3 ~/Library/Mail/Envelope\ Index vacuum .exit
It DOES work. For instance, check how many times Mail.app bounced on the Dock before opening before and after you did this operation. Might prove worthy of use for Yojimbo, too.
Shrink (a bit) winsxs
dism /online /cleanup-image /spsuperseded
Removes SP1 uninstall files.