How do I optimise and set a far-future expiry to Google Fonts and to Gravatars?

Here is my website lin, http://ift.tt/1M8cPx8.

Its analysis on GT Metrix,

http://ift.tt/1QRMU0d

I want to optimise my website, but in YSlow,

There are 5 static components without a far-future expiration date.

http://ift.tt/1Z00gxx
http://ift.tt/1QRMSpe
http://ift.tt/1Z00ftk
http://ift.tt/ZLP1h3
http://ift.tt/PkK5TX

I understand last 2 are analytics and not a good idea to set an expiry for that, but how do I do that for the other too?

I tried pasting the links in W3 Total Cache but doesn't work.