require "xmlrpc/client"

client = XMLRPC::Client.new2('http://www.ruby-lang.org/~nahi/xmlrpc/raa/')

list = info = nil

t1 = Thread.new {
  list = client.call_async("raa.getAllListings")
}

t2 = Thread.new {
  ok, param = client.call2_asnyc("raa.getInfoFromName", "XML-RPC")
  info = param if ok
}

# wait for the threads to complete
t1.join; t2.join

p list, info