It was teased a while back that LG is working on a "rollable" phone. It's not a big surprise they would come up with that eventually, especially they've been showing off an entire rollable TV, so a miniature version as a phone is bound to happen eventually.

The sad part is, LG's rollable phone, is still a concept, a part of their Explorer Project. The idea LG presents here is, a phone that resizes itself into a tablet.
LG has done a few radical stuff with their phones, like, placing the power and volume buttons at the back of the device, right in the middle -- anyone remember those? Weird times. Personally, I was a big fan of it. Then much recently, LG launched their Wing phone, which had two OLED screens, one of which rotated sideways. It was weird, but in a cool kind of way, with its own practical purposes.
But LG isn't alone. We're eying other phone makers out there who have been teasing some interesting concept phones. Whether they become a reality is another question entirely.