diff --git a/AlarmClock/AlarmClock.pde b/AlarmClock/AlarmClock.pde
index dfddbb12..292a1465 100644
--- a/AlarmClock/AlarmClock.pde
+++ b/AlarmClock/AlarmClock.pde
@@ -24,6 +24,7 @@
 #include <FreetronicsLCD.h>
 #include <Form.h>
 #include <Field.h>
+#include <BitBangI2C.h>
 #include <DS1307RTC.h>
 #include <Melody.h>
 
diff --git a/doc/Doxyfile b/doc/Doxyfile
index b578e86b..65bc0669 100644
--- a/doc/Doxyfile
+++ b/doc/Doxyfile
@@ -610,7 +610,7 @@ WARN_LOGFILE           =
 # directories like "/usr/src/myproject". Separate the files or directories
 # with spaces.
 
-INPUT                  = ../libraries/FreetronicsLCD ../libraries/BlinkLED ../libraries/BitBangI2C ../libraries/Melody .
+INPUT                  = ../libraries/FreetronicsLCD ../libraries/BlinkLED ../libraries/I2C ../libraries/RTC ../libraries/Melody .
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is
diff --git a/doc/mainpage.dox b/doc/mainpage.dox
index 58b81d22..6015fd3c 100644
--- a/doc/mainpage.dox
+++ b/doc/mainpage.dox
@@ -34,7 +34,6 @@ LCD shield.
 \li Form and Field classes to build simple property sheet UI's on LCD displays.
 \li \ref lcd_hello_world "Hello World" example for the Freetronics LCD shield.
 \li \ref lcd_form "Form" example for LCD displays.
-\li \ref alarm_clock "Wind-Up Alarm Clock".
 
 \section main_BlinkLED BlinkLED Utility Library
 
@@ -48,4 +47,27 @@ the Cylon eye effect from Battlestar Galactica.
 \li \ref blink_startrek "StarTrek" example for lighting a starship
 Enterprise model kit.
 
+\section main_I2C I2C Utility Library
+
+\li I2CMaster abstract class that provides an improved API for implementing an
+I2C master.  The following two classes inherit from I2CMaster:
+\li BitBangI2C class that implements the master side of the I2C protocol
+using "bit-banging" on any arbitrary pair of pins for DATA and CLOCK.
+This class supports both 7-bit and 10-bit I2C addresses.
+\li WireI2C class that uses the Arduino Wire library to implement the
+master side of the I2C protocol.  This class only supports 7-bit addresses
+and runs on predefined DATA and CLOCK pins (A4 and A5 on most boards,
+D20 and D21 for Arduino Mega).
+
+\section main_RTC Realtime Clock Library
+
+\li RTC class that acts as a base for all realtime clock implementations,
+including support for configuring alarms and storing clock settings.
+The default implementation simulates the time and date based on the value of
+<tt>millis()</tt>.
+\li DS1307RTC class that talks to the DS1307 realtime clock chip via I2C.
+\li \ref alarm_clock "Wind-Up Alarm Clock" example that uses the DS1307
+realtime clock and the FreetronicsLCD library to implement an alarm clock
+where the internal battery is charged by hand-cranking a dynamo.
+
 */
diff --git a/libraries/BitBangI2C/BitBangI2C.cpp b/libraries/I2C/BitBangI2C.cpp
similarity index 100%
rename from libraries/BitBangI2C/BitBangI2C.cpp
rename to libraries/I2C/BitBangI2C.cpp
diff --git a/libraries/BitBangI2C/BitBangI2C.h b/libraries/I2C/BitBangI2C.h
similarity index 100%
rename from libraries/BitBangI2C/BitBangI2C.h
rename to libraries/I2C/BitBangI2C.h
diff --git a/libraries/I2C/keywords.txt b/libraries/I2C/keywords.txt
new file mode 100644
index 00000000..1a81d35d
--- /dev/null
+++ b/libraries/I2C/keywords.txt
@@ -0,0 +1,8 @@
+BitBangI2C	KEYWORD1
+
+start	KEYWORD2
+stop	KEYWORD2
+startRead	KEYWORD2
+startWrite	KEYWORD2
+read	KEYWORD2
+write	KEYWORD2
diff --git a/libraries/BitBangI2C/DS1307RTC.cpp b/libraries/RTC/DS1307RTC.cpp
similarity index 99%
rename from libraries/BitBangI2C/DS1307RTC.cpp
rename to libraries/RTC/DS1307RTC.cpp
index d5e6b441..e59cb700 100644
--- a/libraries/BitBangI2C/DS1307RTC.cpp
+++ b/libraries/RTC/DS1307RTC.cpp
@@ -21,6 +21,7 @@
  */
 
 #include "DS1307RTC.h"
+#include "../I2C/BitBangI2C.h"
 #include <WProgram.h>
 
 /**
diff --git a/libraries/BitBangI2C/DS1307RTC.h b/libraries/RTC/DS1307RTC.h
similarity index 98%
rename from libraries/BitBangI2C/DS1307RTC.h
rename to libraries/RTC/DS1307RTC.h
index 767eda5c..25a2ea78 100644
--- a/libraries/BitBangI2C/DS1307RTC.h
+++ b/libraries/RTC/DS1307RTC.h
@@ -24,7 +24,8 @@
 #define DS1307RTC_h
 
 #include "RTC.h"
-#include "BitBangI2C.h"
+
+class BitBangI2C;
 
 class DS1307RTC : public RTC {
 public:
diff --git a/libraries/BitBangI2C/RTC.cpp b/libraries/RTC/RTC.cpp
similarity index 100%
rename from libraries/BitBangI2C/RTC.cpp
rename to libraries/RTC/RTC.cpp
diff --git a/libraries/BitBangI2C/RTC.h b/libraries/RTC/RTC.h
similarity index 100%
rename from libraries/BitBangI2C/RTC.h
rename to libraries/RTC/RTC.h
diff --git a/libraries/BitBangI2C/keywords.txt b/libraries/RTC/keywords.txt
similarity index 68%
rename from libraries/BitBangI2C/keywords.txt
rename to libraries/RTC/keywords.txt
index d1828dbd..8c4bc60e 100644
--- a/libraries/BitBangI2C/keywords.txt
+++ b/libraries/RTC/keywords.txt
@@ -1,14 +1,6 @@
-BitBangI2C	KEYWORD1
 DS1307RTC	KEYWORD1
 RTC	        KEYWORD1
 
-start	KEYWORD2
-stop	KEYWORD2
-startRead	KEYWORD2
-startWrite	KEYWORD2
-read	KEYWORD2
-write	KEYWORD2
-
 isRealTime	KEYWORD2
 hasUpdates	KEYWORD2
 readTime	KEYWORD2