Do you keep your ketchup in the fridge or in the cupboard? I always kept it on the cupboard until I moved here, then a succession of foreign girlfriends made me change my ways. Now I prefer it cold!
Cupboard - always have. It's got vinegar in which preserves it. When the missus moved here she started keeping it in the fridge until she decided that 1. The fridge here is too small compared to US fridges, so limited on fridge space. 2. I'd obviously not died of food poisoning in all the years of keeping it in the cupboard. Mayo is different as that is egg based. Also, I don't want cold ketchup on my chips or cold brown sauce on a bacon sarnie. Salad cream is fine cold as it's going on salad.
Always kept in cupboard, until the wife came along and now nearly everything has to be kept refrigerated. Bat **** mental.
A special area in my pantry that houses all my sauces - probably about 20-30, including ketchup, brown, reggae reggae, bbq, and many variations on chilli. As Eaststander says, I don't see why you would put something on your chips, burger etc that is fridge-cold, they will only go cold quicker.
Funnily enough, I'm house sitting for a fortnight and just happened to notice yesterday that the ketchup was in the fridge, and I thought it was the most bizarre thing I'd ever seen.