Andrew,
The fastest way to get going is to use ns_xmlrpc in AOLserver, and TclSOAP in tclsh (using the xmlrpc implementation).
ns_xmlrpc has very little error checking code built in though, so you might want to look into that. It would be fine for testing. I really don't plan on developing it furhter, because TclSOAP is much more mature, and support xmlrpc and soap using the same code, so it is a much better long-term solution.