Google, the online giant, and Ipsos, the survey firm, polled 6,000 people in six countries, and found smartphone uptake has hit 45% in the UK, 44% in Spain, 38% in France and the US, 23% in Germany and 17% in Japan.
Some 48.3% of respondents with smartphones used them while watching TV, as did 44% when listening to music on the radio, 24% during movies and 15% alongside playing video games and reading print media.
In all, 81% of American smartphone subscribers engaged in some form of simultaneous media use, standing at 74% for the UK, 72% for France, Spain and Japan, and 69% for Germany.
Over 94% of individuals owning gadgets like the iPhone or alternatives powered by Google's Android in each market had gone online via these devices in the seven days prior to the research.
The Japanese panel typically had the highest number of apps installed on their smartphones, with 42. The average US user had 26, with the UK and Germany both on 23 and Spain on 19.
But German customers typically had the greatest amount of paid-for applications, averaging out at nine, falling to six across all the other countries assessed.
Turning to m-commerce, 40% of Japan's smartphone audience had purchased something in this way. Totals here stood at 34% when discussing the US, 30% in relation to the UK, 37% for Germany and 24% in France and Spain.
More broadly, 25% of consumers "intentionally" carried their smartphone when shopping to compare prices and products, and 21% had changed their mind about an in-store purchase due to information gained through this route.
In all, 22% of people that researched products using a smartphone had ultimately made the related purchase via the same channel. A further 35% bought the items concerned using a computer and 24% for doing so offline.
A further 49% had searched for information on their phone after seeing in-store marketing, coming in at 52% for TV ads, 44% for magazines advertising and 39% for out-of-home posters.
When discussing which mobile ad formats they noticed, 34% pointed to paid search, 37% flagged up in-app alternatives and 44% referenced website display, easily the top three on this measure.
Data sourced from Google; additional content by Warc staff, 29 February 2012