Explicitly set the arch on i386 Leopard.

ext/extconf.rb

@@ -6,25 +6,32 @@ if ENV['SWIG']
   $stdout.write `swig -I/opt/local/include -ruby -autorename rlibmemcached.i`
 end
 
+if `uname -sp` == "Darwin i386\n"
+  $CFLAGS.gsub! /-arch \S+/, ''
+  $CFLAGS << " -arch i386"
+  $LDFLAGS.gsub! /-arch \S+/, ''
+  $LDFLAGS << " -arch i386"
+end
+
 $CFLAGS.gsub! /-O\d/, ''
 
 if ENV['DEBUG']
   puts "setting debug flags"
-  $CFLAGS << " -O0 -ggdb -DHAVE_DEBUG" 
+  $CFLAGS << " -O0 -ggdb -DHAVE_DEBUG"
 else
   $CFLAGS << " -O3"
 end
 
-find_library(*['memcached', 'memcached_server_add', dir_config('libmemcached').last].compact) or
+find_library(*['memcached', 'memcached_server_add_with_weight', dir_config('libmemcached').last].compact) or
   raise "shared library 'libmemcached' not found"
 
-[ 
+[
   'libmemcached/memcached.h',
-  'libmemcached/memcached_constants.h', 
+  'libmemcached/memcached_constants.h',
   'libmemcached/memcached_storage.h',
   'libmemcached/memcached_result.h',
   'libmemcached/memcached_server.h'
-].each do |header|  
+].each do |header|
     find_header(*[header, dir_config('libmemcached').first].compact) or
       raise "header file '#{header}' not  found"
 end