--- logger.rb.orig	2011-01-16 03:33:40.464288002 -0800
+++ logger.rb	2011-01-16 03:59:01.245288002 -0800
@@ -124,11 +124,15 @@
 #
 #      logger.error "Argument #{ @foo } mismatch."
 #
-# 3. With progname.
+# 3. Message as a format string.
+#
+#      logger.debug ["User-input: %p", input]
+#
+# 4. With progname.
 #
 #      logger.info('initialize') { "Initializing..." }
 #
-# 4. With severity.
+# 5. With severity.
 #
 #      logger.add(Logger::FATAL) { 'Fatal error!' }
 #
@@ -374,6 +378,9 @@
   #   logger.info "Waiting for input from user"
   #   # ...
   #   logger.info { "User typed #{input}" }
+  #   # ...
+  #   logger.info ["User input: %p", input]
+  #   # ...
   #
   # You'll probably stick to the second form above, unless you want to provide a
   # program name (which you can do with <tt>Logger#progname=</tt> as well).
@@ -472,6 +479,8 @@
       case msg
       when ::String
         msg
+      when ::Array
+        msg[0] % msg[1..-1]
       when ::Exception
         "#{ msg.message } (#{ msg.class })\n" <<
           (msg.backtrace || []).join("\n")