This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
XML-RPC is a more light-weight protocol for making RPC calls using XML over HTTP. Web services is heavier but also more rich in functionality (there's plenty of WS- prefixed specifications coming our way...).