If you find yourself running low on space on your phone and need a handy way to extend your storage you could consider the Samsung Wireless HDD.  A mere 19.9x89x126.5mm and 275g it won't take up a lot of space but will allow up to five devices to connect over 802.11 b/g/n WiFi to stream the content stored on the drive.  It also has USB 3.0 connectivity to help you load up the drive before you head out on the road and you can even steal some of it's 7 hour rated battery life by using it as a charging station for your phone.  Kitguru tested multiple streams and found that two simultaneous connections work perfectly but it is best not to exceed streaming to a pair of devices.  The five device rating seems to refer more to the number of saved connections than to the number of streams you can run.

"While many users these days may have several terabytes of PC storage space, mobile storage is yet to catch up. Many phones come with just 16GB of internal storage, while 128GB is just about as good as it gets. This means most users simply cannot fit their media collections on their mobile devices – which is far from ideal."

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Storage