diff --git a/src/apps/activitymonitor/DataSource.cpp b/src/apps/activitymonitor/DataSource.cpp
index 65096e4232..4b082015bc 100644
--- a/src/apps/activitymonitor/DataSource.cpp
+++ b/src/apps/activitymonitor/DataSource.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright 2008, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
+ * Copyright 2008-2009, Axel Dörfler, axeld@pinc-software.de.
  * Distributed under the terms of the MIT License.
  */
 
@@ -24,6 +24,7 @@ const DataSource* kSources[] = {
 	new CPUCombinedUsageDataSource(),
 	new NetworkUsageDataSource(true),
 	new NetworkUsageDataSource(false),
+	new BlockCacheDataSource(),
 	new SemaphoresDataSource(),
 	new PortsDataSource(),
 	new ThreadsDataSource(),
@@ -450,6 +451,54 @@ SwapSpaceDataSource::Primary() const
 //	#pragma mark -
 
 
+BlockCacheDataSource::BlockCacheDataSource()
+{
+	fColor = (rgb_color){0, 120, 0};
+}
+
+
+BlockCacheDataSource::~BlockCacheDataSource()
+{
+}
+
+
+DataSource*
+BlockCacheDataSource::Copy() const
+{
+	return new BlockCacheDataSource(*this);
+}
+
+
+int64
+BlockCacheDataSource::NextValue(SystemInfo& info)
+{
+	system_memory_info memoryInfo;
+	status_t status = get_system_info_etc(B_MEMORY_INFO, &memoryInfo,
+		sizeof(system_memory_info));
+	if (status != B_OK)
+		return 0;
+
+	return memoryInfo.block_cache_memory;
+}
+
+
+const char*
+BlockCacheDataSource::Label() const
+{
+	return "Block Cache Memory Usage";
+}
+
+
+const char*
+BlockCacheDataSource::ShortLabel() const
+{
+	return "Block Cache";
+}
+
+
+//	#pragma mark -
+
+
 SemaphoresDataSource::SemaphoresDataSource()
 {
 	SystemInfo info;
diff --git a/src/apps/activitymonitor/DataSource.h b/src/apps/activitymonitor/DataSource.h
index d4d1e91cdc..0a6d3ef9e8 100644
--- a/src/apps/activitymonitor/DataSource.h
+++ b/src/apps/activitymonitor/DataSource.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2008, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
+ * Copyright 2008-2009, Axel Dörfler, axeld@pinc-software.de.
  * Distributed under the terms of the MIT License.
  */
 #ifndef DATA_SOURCE_H
@@ -115,6 +115,19 @@ public:
 };
 
 
+class BlockCacheDataSource : public MemoryDataSource {
+public:
+						BlockCacheDataSource();
+	virtual				~BlockCacheDataSource();
+
+	virtual DataSource*	Copy() const;
+
+	virtual	int64		NextValue(SystemInfo& info);
+	virtual const char*	Label() const;
+	virtual const char*	ShortLabel() const;
+};
+
+
 class SemaphoresDataSource : public DataSource {
 public:
 						SemaphoresDataSource();