Pictures of the alleged nano SIM card tray of iPhone 5 have been leaked .
The nano-SIM design requires 40% less space , thus saving more space for other internals of modern smartphones . The new alleged tray of iPhone 5 shows the difference in size between micro SIM and nano SIM .
Also if the pics are authentic , the black color hints that the new iPhone will have black sides and white sides instead of grey metallic sides on the current designs .
The iPhone 5's alleged home button's pictures have also surfaced . The design is same but it has apparently become smaller , to make more room for the larger display .
Source
The nano-SIM design requires 40% less space , thus saving more space for other internals of modern smartphones . The new alleged tray of iPhone 5 shows the difference in size between micro SIM and nano SIM .

Also if the pics are authentic , the black color hints that the new iPhone will have black sides and white sides instead of grey metallic sides on the current designs .

The iPhone 5's alleged home button's pictures have also surfaced . The design is same but it has apparently become smaller , to make more room for the larger display .

Source