RoboSpice is a modular android library that makes writing asynchronous network requests easy.
It supports REST requests out of the box using Spring Android (other implementations are possible as well).
Sample demo app available on the market : http://goo.gl/pzqH4
RoboSpice uses a new approach : it executes network requests inside an Android Service.
To learn more about RoboSpice in 30 seconds, have a look at this infographics : http://goo.gl/jxNin
Activities (or other contexts) can bind very easily to the RoboSpice Service to add new requests, cancel requests, etc.
RoboSpice provides automatic caching of requests' results, various formats are supported.
Main features of RoboSpice:
RoboSpice's GitHub repo contains sources, javadoc, sample app, presentation slides, infographics, even a DIY T-shirt !
RoboSpice is maven-ready : http://search.maven.org/#search%7Cga%7C1%7Crobospice