Poland
Being a vegan in Poland can be hard because there is a lot of people who do not tolerate that we are different however it is not impossible and I believe the number of vegans are growing. You will still find many people who don't know what vegan means, some people still didn't hear about vegetarianism, mostly in small localities.
Vegan friendly restaurants in Warsaw http://weganwawa.wordpress.com/category/restauracje/
Groups
The best known Polish group promoting veganism is EMPATIA