Future-http is a project mainly written in SCALA and SHELL, it's free.
Experimentation of different ways to do parallel http access in scala
To build:
download sbt following instructions at http://code.google.com/p/simple-build-tool/wiki/Setup
sbt update
sbt test
The tests are the interesting thing here. And I've probably committed with quite a few ignored, take a look and enable the interesting ones.