NanoHttpd is a lightweight HTTP server designed for embedding in other applications. It's only one Java file, in two "flavors", one strictly Java 1.1 compatible, and one at "current" standards. It supports GET, POST, PUT, HEAD and DELETE requests, and supports file uploading with very small memory overhead. Temp file usage and the threading model are easily customized.
RoboZombie allows easy integration with remote services by allowing you to replicate an endpoint contract and generate a proxy to access it. Contracts can be very flexible in terms of the resources they access. These could be vary from static HTML content or an RRS feed, to a RESTful web service endpoint. Each endpoint contract is specified on a single interface using annotations to provide the communication metadata. It is then wired into your code via an annotation, where it is created, cached, and injected at runtime.