It is very simple actually (although not as fast as using a dedicated web server like nginx). Just use python:
python -m SimpleHTTPServer
That's it ! After running this line, the files in your current folder will be accessible over port 8000, so you can send your pears a link like this: http://YourIPHere:8000/ , and they will be able to read the shared folder.
You can change the port very easily too - just append it at the end of the last command, like this :
python -m SimpleHTTPServer 11001
That will run a webserver for the current folder over port 11001, instead of the default port 8000.
Stopping the python webserver process is simple too - just type Ctrl-C, like you would do for any other long running shell process.