PokerTracker

How can I delete all Cash game hands but keep all tourney hands?

There is not yet a selective purge.
The only way to do this at the moment would be to export all hands (Database Management, select DB, "Export") then import just the tournament hands from the export.
When you export like this, the files are split into folders for each site, and include "cash" (and, I assume "tournament") in the file names, so you should be able to pull out the files you want to another folder and manually import them into another DB.

that'll do, thanks!