How do I change the default font in Calc?

the default font for calc is arial 10. how can I change this default to a different font?

libre office 3.3.4 OOO330m 19(build:401-401-202) tag libre office-3.3.3.1,
ubuntu package 1:3.3.3.4-Oubuntu1

Problem solved.

And I’ve updated that answer for LO 4.0.x: http://superuser.com/a/610511/217553

Not actually an answer, just an update to the question. In version 5.0.2.2 Writer lets you change the default fonts from the options menu, no need to muck about with making a template. But Calc doesn’t offer the option, at least that I can find. Is there a simple option to change the default font for Calc or is a new template the only way?