The most original way would be the trusty "print screen" button.
Afterwards you can paste the print screen image into MS Paint or IrfanView.
The best option would be to install "Virtual Image Printer Driver
" (works only on Windows).
Then you can convert ANY document into JPG images.
This program is Open Source, free
The easiest option is to use an online PDF to JPG converter
, no need to install any software and you can simply share the url with your friends.
Another option in my mind is to upload it to Google Docs and share it there.
Just my 50 cents. Good luck!