According to some very recent uSwitch.com Mobile Tracker search data, the Samsung Galaxy S III has displaced the Apple iPhone 4S as the "most popular" device in the UK, at least according to how many people are searching the web for info related to the phones. While this is hardly the only data required to jump to the conclusion that the SGS3 is more popular than the iPhone 4S, it is still worthy of consideration as an intriguing factor in the overall picture. Interestingly if you look deeper at this particular gauge for success, then Sammy and Apple have been playing hopscotch. Here's a quote with a few more details,

The iPhone 4S replaced the previous model, the Galaxy S2, last month, but the S3 pushed it down to second place on its first appearance in the online chart. HTC’s One Series handsets now feature three times in the top ten, while Sony retains just one phone on the list, with its Xperia S at number ten. The Samsung Galaxy S2 had been at number one for 11 consecutive months; it is now at number three, meaning Samsung takes four of the top ten places thanks to the Ace at five and the Note at six. Apple’s iPhone 4S is at two, while the iPhone 4 is at seven.
Here's the full list:

Top Ten Handsets for March by web search
1 Samsung Galaxy S III
2 iPhone 4S (16GB)
3 Samsung Galaxy S II
4 HTC One X
5 Samsung Galaxy Ace
6 Samsung Galaxy Note
7 iPhone 4 (16GB)
8 HTC One S
9 HTC One V
10 Sony Xperia S
Thanks for the tip, Ollie!

Source: S3Forums.com via TheTelegraph