Big things can come in very, very small packages. Case in point: SanDisk has just released a 200GB microSDXC card, which is as absurdly tiny as the rest of them but offers the most storage to date for the format.
Previously, the largest microSD card type available offered 128GB of unformatted storage, but this latest version adds more than 50% additional capacity. The 200GB version was announced back in March, and SanDisk says the 90MB/second read speed allows approximately 1200 photos to be transferred via USB 3.0 in a minute.
Granted, all that capacity comes at a price, and removable storage is never cheap - especially at first. The 200GB card sells for £210 from Amazon, whereas the 128GB version is just £58. You could buy three of those for less and have loads more storage, but of course, swapping (and storing) tiny cards like these is problematic.
Another thing worth considering is whether your device can even handle a 200GB card. Many recent smartphones say they only take 128GB cards, but those specs were established before the 200GB card existed. That said, LG's G4 and G Flex 2 and the HTC One M9 all claim to take up to 2TB cards - which clearly do not yet exist - so they'll be fine.
Snagging the 200GB card comes at a very pricey premium over the next-lowest option, but if you're intent on keeping a whole wealth of files in your pocket at all times, SanDisk's microSD monster could be tempting.