Here's a nice little Perl client from the HOWTO, written using Ken MacLeod's Frontier::RPC2 package:
$server_url = 'http://betty.userland.com/RPC2';
$server = Frontier::Client->new(url => $server_url);
$name = $server->call('examples.getStateName', 41);
Took a look at SOAP (a related protocol), and decided that the W3C overdesigns everything to the point of insanity. So for now, I'm going to take Larry Wall's(?) "bear of little brain" approach: If I can't figure it out in half an hour or so, it probably sucks.
School: Latin quiz tomorrow. Ick!