> I don't have the degree circle on my keyboard (Danish), where does it
> tend to be?
On my (GB layout) keyboard, its "<AltGr><shift>0" (zero).
I did a quick check in the code. Double apostrophe works too for minutes. Furthermore, for convenience, GRAMPS allows you to use the # symbol for degrees as well as . Obviously that does not print so nicely in output :-)
So, you can use °, º or # and for minutes " or '' as well as some exotic utf codes. You can also input the value of degrees in colon notation like you know from watches: 40:20:1