I'm involved in the fixing of an Online Dating Service.
They have a registration form (all fields required), and 11 fields out of 16 are comboboxes.
The fields are (in order, with comboboxes in emphasis):
- first name
- nickname
- gender (2 options: male or female)
- (looking for)type of relationship (3 options: get to know, adventure, serious)
- birthday (3 combos, Y/M/D)
- place of residence
- body shape (8 options, from thin to fit to obese)
- height (from 120 to 230, opening at 170)
- sport activities (4 options: professional, regular, sometimes, none)
- highest education (6 options from primary school to university, this is specific to country)
- smoking (4 options: yes, sometimes, only at parties, no)
- Mother tongue (100+ options, the only one with a default answer)
- Other languages spoken (a dropdown with checkboxes, looking like a combobox)
- Marital status (4 options: single, divorced, widowed, married, local custom)
- Password
- Password again
And the whole thing looks like this:
One by one, most of the select boxes are justifiable by the UX jargon:
- It's said birthday should be asked this way (according to Joe Leech on Smashing Magazine)
- It's said that when you have around 4-6 options, it should be a combobox (that was somewhere here, but also in the web form design book)