I am fidling around with RPC::XML (an xml-rpc implementation for Perl) - which seemed the most usable of xml-rpc/soap thingies out there in the perl world.

Are you sure XML::RPC is easier to use than SOAP::Lite? I have little practical experience in the domain, but it looks like SOAP::Lite is quite easy to use, and soaplite.com has quite a bit of documentation, including a cookbook.

For both SOAP::Lite and XML::RPC you could read Programming Web Services with Perl, and have a look at the companion website.