At the moment I'm on holiday in Antigua and due to a heavy American influence here, there is a fierce usage of imperial /US customary measurements. Goods in supermarkets are sold by the pound and ounce, the speed limits are in miles per hour -national speed limit being 40 miles per hour( rounded to 65 km/h) - in spite of the majority of cars featuring km/h only speedometers. However, say the word metre and it's like you're speaking a foreign language.
Excluding the use of the litre, the metric system is practically unused here outside of schools, and it is not understood by the vast majority of the residents.
What's interesting however, Antigua has officially gone metric within the last 5 years. The only evidence of this, can be seen in the direction signage, which shows distance in kilometres (and fractions thereof - something which is technically incorrect according to the BIPM's guidelines). I believe they were erected with distances marked in kilometres because of the Cricket World Cup in 2006. People objected to them, initially, but now have no choice but to get used to them. (Although in a country that's only 281 square kilometres, distances are not that important.)
In Britain, we have a Catalyst (the OLYMPICS) and should use that to metricate our signs. The country has been metric for all of my life, yet the use of miles and yards still lingers on. Utterly pointless!