diff --git a/Makefile.am b/Makefile.am
index de292f44..e21b97d0 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -21,6 +21,7 @@ UTIL_INCLUDE =  \
     point.hpp	\
     range.hpp	\
     region.hpp	\
+    signal.hpp	\
     stream.hpp	\
     types.hpp	\
     vector.hpp  \
@@ -38,6 +39,7 @@ UTIL_FILES   =	\
     point.cpp	\
     range.cpp	\
     region.cpp	\
+    signal.cpp	\
     stream.cpp	\
     types.cpp	\
     vector.cpp  \
diff --git a/signal.cpp b/signal.cpp
new file mode 100644
index 00000000..d9e293b4
--- /dev/null
+++ b/signal.cpp
@@ -0,0 +1,22 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libgim is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with libgim.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2011 Danny Robson <danny@blubinc.net>
+ */
+
+
+#include "signal.hpp"
+
diff --git a/signal.hpp b/signal.hpp
new file mode 100644
index 00000000..b6a480e9
--- /dev/null
+++ b/signal.hpp
@@ -0,0 +1,70 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libgim is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with libgim.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2011 Danny Robson <danny@blubinc.net>
+ */
+
+#ifndef __SIGNAL_HPP
+#define __SIGNAL_HPP
+
+#include <algorithm>
+#include <vector>
+#include <functional>
+
+
+template <typename Ret, typename ...Args>
+class signal {
+    public:
+        typedef Ret (*callback_function)(Args...);
+        typedef std::function<Ret(Args...)> callback_object;
+
+    protected:
+        std::vector<callback_object> m_children;
+
+    public:
+        signal ()
+            { m_children.reserve (16); }
+
+        /// Add a callback to list.
+        void connect (callback_object _cb)
+            { m_children.push_back (_cb); }
+        void connect (callback_function _cb)
+            { m_children.push_back (_cb); }
+
+        /// Remove all instances of callback `cb'
+        void disconnect (callback_function _cb)
+            { disconnect (callback_object (_cb)); }
+
+        /// Remove all instances of callback `cb'
+        void disconnect (callback_object _cb) {
+            m_children.erase (std::remove (m_children.begin (),
+                                           m_children.end   (),
+                                           _cb),
+                              m_children.end ());
+        }
+
+        /// Remove all callbacks
+        void clear (void)
+            { m_children.clear (); }
+
+        /// Execute all callbacks. Does not combine results.
+        void operator () (Args&... tail) {
+            for (auto i = m_children.begin (), end = m_children.end (); i != end; ++i)
+                (*i)(tail...);
+        }
+};
+
+#endif // __SIGNAL_HPP
diff --git a/test/.gitignore b/test/.gitignore
index 5407c90c..a82d7fb0 100644
--- a/test/.gitignore
+++ b/test/.gitignore
@@ -6,4 +6,5 @@
 /maths
 /matrix
 /range
+/signal
 /version
diff --git a/test/Makefile.am b/test/Makefile.am
index d3887ac0..efccdd5b 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -7,35 +7,48 @@ AM_CPPFLAGS =                   \
 
 AM_LDFLAGS  = $(COMMON_LDFLAGS)
 
-TEST_BIN = backtrace float range maths matrix version ip hton
+TEST_BIN = 		\
+	backtrace 	\
+	float		\
+	hton		\
+	ip 		\
+	maths 		\
+	matrix 		\
+	range 		\
+	signal		\
+	version
+
 TESTS = $(TEST_BIN) json.pl
 check_PROGRAMS = $(TEST_BIN) json-check
 EXTRA_DIST = json.pl
 
-backtrace_SOURCES  = backtrace.cpp
 backtrace_CPPFLAGS = $(COMMON_CXXFLAGS)
-backtrace_LDADD    = $(builddir)/../libutil.la $(BOOST_SYSTEM_LIB)
+backtrace_LDADD    = $(builddir)/../libutil.la
+backtrace_SOURCES  = backtrace.cpp
 
+float_LDADD        = $(builddir)/../libutil.la
 float_SOURCES      = float.cpp
-float_LDADD        = $(builddir)/../libutil.la $(BOOST_SYSTEM_LIB)
-
-range_SOURCES 	   = range.cpp
-range_LDADD        = $(builddir)/../libutil.la $(BOOST_SYSTEM_LIB)
-
-maths_SOURCES      = maths.cpp
-maths_LDADD        = $(builddir)/../libutil.la $(BOOST_SYSTEM_LIB)
-
-matrix_SOURCES     = matrix.cpp
-matrix_LDADD       = $(builddir)/../libutil.la $(BOOST_SYSTEM_LIB)
-
-version_SOURCES    = version.cpp
-version_LDADD      = $(builddir)/../libutil.la $(BOOST_SYSTEM_LIB)
-
-ip_SOURCES         = ip.cpp
-ip_LDADD      	   = $(builddir)/../libutil.la $(BOOST_SYSTEM_LIB)
 
+hton_LDADD	   = $(builddir)/../libutil.la
 hton_SOURCES	   = hton.cpp
-hton_LDADD	   = $(builddir)/../libutil.la $(BOOST_SYSTEM_LIB)
 
-json_check_SOURCES = json-check.cpp
+ip_LDADD      	   = $(builddir)/../libutil.la
+ip_SOURCES         = ip.cpp
+
 json_check_LDADD   = $(builddir)/../libutil.la $(BOOST_FILESYSTEM_LIB)
+json_check_SOURCES = json-check.cpp
+
+maths_LDADD        = $(builddir)/../libutil.la
+maths_SOURCES      = maths.cpp
+
+matrix_LDADD       = $(builddir)/../libutil.la
+matrix_SOURCES     = matrix.cpp
+
+range_LDADD        = $(builddir)/../libutil.la
+range_SOURCES 	   = range.cpp
+
+signal_LDADD	   = $(builddir)/../libutil.la
+signal_SOURCES     = signal.cpp
+
+version_LDADD      = $(builddir)/../libutil.la
+version_SOURCES    = version.cpp
diff --git a/test/signal.cpp b/test/signal.cpp
new file mode 100644
index 00000000..89fa04b7
--- /dev/null
+++ b/test/signal.cpp
@@ -0,0 +1,50 @@
+#include <cstdlib>
+
+#include "../signal.hpp"
+#include "../debug.hpp"
+
+void
+increment_uint (unsigned int &val)
+    { ++val; }
+
+
+void
+test_null (void) {
+    signal<void> void_signal;
+    void_signal ();
+}
+
+
+void
+test_single (void) {
+    unsigned int val = 0;
+    signal<void, unsigned int&> void_signal;
+
+    void_signal.connect (increment_uint);
+    void_signal (val);
+
+    check_eq (val, 1);
+}
+
+
+void
+test_double (void) {
+    unsigned int val = 0;
+    signal<void, unsigned int&> void_signal;
+
+    void_signal.connect (increment_uint);
+    void_signal.connect (increment_uint);
+    void_signal (val);
+
+    check_eq (val, 2);
+}
+
+
+int
+main (int, char **) {
+    test_null   ();
+    test_single ();
+    test_double ();
+
+    return EXIT_SUCCESS;
+}