i have the z1 and cant find the part of the menu that lets me switch between modes...

It's in the menu window, scroll down to the four squares and click on them.

You'll see a 50i/60i sel choice.

P.S. The four squares are called 'The Others' menu.

wow for some reason all tihs time i thought the z1 could shoot progressive, it only can switch between 50 and 60 i?

Not sure where you got that idea, there have never been any claims that the Z1 could shoot progressive. The Z1 does have the "cineframe" modes however - cf24, cf25 and cf30. More information about those can be found here: http://www.adamwilt.com/HDV/cineframe.html

It's not a good idea to switch between 60i and 50i on the same tape. The timecode formats and data on the tape would conflict during previewing on the machine and capture.