diff --git a/library/flood.py b/library/flood.py
index 8b16013b2..72992b7d1 100644
--- a/library/flood.py
+++ b/library/flood.py
@@ -468,31 +468,18 @@ class manager:
 			except AttributeError:
 				pass
 
-	# Advanced statistics
+	# Advanced statistics - these may be SLOW. The client should call these only
+	# when needed, and perhaps only once in a long while (they are mostly just
+	# approximations anyhow
 
-	# Availability - how many complete copies are among our peers
 	def calc_availability(self, unique_ID):
-		peer_info = self.get_core_torrent_peer_info(unique_ID)
+		return flood_stats.calc_availability(self.get_core_torrent_peer_info(unique_ID))
 
-		if len(peer_info) == 0:
-			return 0
-
-		num_pieces = len(peer_info[0].pieces)
-
-		freqs = [0]*num_pieces
-
-		for peer in peer_info:
-			for piece in num_pieces:
-				freqs[piece] = freqs[piece] + peer['pieces'][piece]
-
-		minimum = min(freqs)
-#		frac = freqs.count(minimum + 1) # Does this mean something?
-
-		return minimum
-
-	# Swarm speed - try to guess the speed of the entire swarm
 	def calc_swarm_speed(self, unique_ID):
-		pass
+		pieces_per_sec = flood_stats.calc_swarm_speed(self.get_core_torrent_peer_info(unique_ID))
+		piece_length   = self.get_core_torrent_state(unique_ID, efficiently=True)
+
+		return pieces_per_sec * piece_length
 
 	# Miscellaneous minor functions
 
diff --git a/library/flood_stats.py b/library/flood_stats.py
new file mode 100644
index 000000000..6c3a1cf8a
--- /dev/null
+++ b/library/flood_stats.py
@@ -0,0 +1,78 @@
+# 
+# Copyright (C) 2006 Alon Zakai ('Kripken') <kripkensteiner@gmail.com>
+#
+# This program 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 2, or (at your option)
+# any later version.
+# 
+# This program 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 this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+#
+
+import time
+
+# Global variables. Caching of saved data, mostly
+
+old_peer_info           = None
+old_peer_info_timestamp = None
+
+# Availability - how many complete copies are among our peers
+def calc_availability(peer_info):
+	if len(peer_info) == 0:
+		return 0
+
+	num_pieces = len(peer_info[0].pieces)
+
+	freqs = [0]*num_pieces
+
+	for peer in peer_info:
+		for piece in num_pieces:
+			freqs[piece] = freqs[piece] + peer['pieces'][piece]
+
+	minimum = min(freqs)
+#		frac = freqs.count(minimum + 1) # Does this mean something?
+
+	return minimum
+
+# Swarm speed - try to guess the speed of the entire swarm
+# We return #pieces / second. The calling function should convert pieces to KB, if it wants
+# Note that we return the delta from the last call. If the client calls too soon, this may
+# be too unreliable. But the client can smooth things out, if desired
+def calc_swarm_speed(peer_info):
+	if old_peer_info is not None:
+		new_pieces  = 0
+		peers_known = 0
+
+		# List new peers
+		new_peer_IPs = {} # ip->peerinfo dict (from the core)
+		for peer in peer_info:
+			new_peer_IPs[peer['ip']] = peer
+
+		for new_IP in new_peer_IPs.keys():
+			if new_IP in old_peer_IPs.keys():
+				# We know this peer from before, see what changed
+				peers_known = peers_known + 1
+				delta       = sum(new_peer_IPs[new_IP].pieces) - sum(old_peer_IPs[new_IP].pieces)
+
+				if delta >= 0:
+					new_pieces  = new_pieces + delta
+				else:
+					print "Flood.stat.calc_swarm_speed: Bad Delta: ", delta, old_peer_IPs[new_IP].pieces, new_peer_IPs[new_IP].pieces
+
+	# Calculate final value
+	time_delta = time.time() - old_peer_info_timestamp
+	ret = float(new_pieces)/( float(peers_known) * time_delta )
+
+	# Save info
+	old_peer_info           = peer_info
+	old_peer_info_timestamp = time.time()
+	old_peer_IPs            = new_peer_IPs
+
+	return ret