But just 0.77 per cent are sharing their location with GPS.
Twitter has cemented its silver medal in the social network stakes, crossing the half billion user milestone in June, according to social media analyst Semiocast.
Of course, Facebook is the champion, following last week's reveal that it has 955 million monthly users, with 543m logging on via mobiles.
More than 140m users – 27.4 per cent – are based in the US, while the top three cities for number of tweets are Jakarta, Tokyo, and London.
The latter location isn't surprising, given that there are more than 10m Twitter users in the UK, with 80 per cent tweeting from mobiles.
However, while GPS is considered to be a growing commodity in the tech world, just 0.77 per cent of users opt to share their whereabouts with users, over two and a half years after the feature was launched.
Check out the graphs below.