Nginx doesn't generate etags for static content. I think it should. If I can remember enough C from college to make it work as a module, I will.

Download the module however you like. I'd recommend pulling it down with Git by simply cloning this repository:

mkdir ~/src
cd    ~/src
git clone git://github.com/mikewest/nginx-static-etags.git ./nginx-static-etags

To use the module, you'll have to compile it into Nginx. So, download the Nginx source, configure it with the module path, and compile:

mkdir ~/src
cd ~/src
curl -O http://sysoev.ru/nginx/nginx-0.6.32.tar.gz
tar -zxvf ./nginx-0.6.32.tar.gz
cd ./nginx-0.6.32
./configure --add-module=/Users/mikewest/Repositories/nginx-static-etags
make
sudo make install

And you're done!

Add FileEtag to the relevant location blocks in your nginx.conf file:

location / {
    ...
    FileETag on;
    ...
}

It's currently an on/off toggle. The plan is to bring it to feature parity with the Apache configuration option. It's really not there yet.