diff --git a/tradedb.py b/tradedb.py
index 380a63e4..2e8dddbb 100644
--- a/tradedb.py
+++ b/tradedb.py
@@ -62,6 +62,19 @@
 import sqlite3
 import sys
 
+try:
+    import numpy
+    import numpy.linalg
+    haveNumpy = True
+except ImportError:
+    class numpy(object):
+        array = False
+        float32 = False
+        ascontiguousarray = False
+        class linalg(object):
+            norm = False
+    haveNumpy = False
+
 locale.setlocale(locale.LC_ALL, '')
 
 
@@ -132,7 +145,7 @@ class System(object):
 
     __slots__ = (
         'ID',
-        'dbname', 'posX', 'posY', 'posZ', 'stations',
+        'dbname', 'posX', 'posY', 'posZ', 'pos', 'stations',
         'addedID',
         '_rangeCache'
     )
@@ -145,10 +158,16 @@ def __init__(self):
             self.systems = []
             self.probedLy = 0.
 
-    def __init__(self, ID, dbname, posX, posY, posZ, addedID):
+    def __init__(
+            self, ID, dbname, posX, posY, posZ, addedID,
+            ary=numpy.array,
+            nptype=numpy.float32,
+            ):
         self.ID = ID
         self.dbname = dbname
         self.posX, self.posY, self.posZ = posX, posY, posZ
+        if haveNumpy:
+            self.pos = ary([posX, posY, posZ], nptype)
         self.addedID = addedID or 0
         self.stations = ()
         self._rangeCache = None
@@ -211,6 +230,19 @@ def distanceTo(self, other):
             (self.posZ - other.posZ) ** 2
         ) ** 0.5  # fast sqrt
 
+    if haveNumpy:
+        def all_distances(
+                self, iterable,
+                ary=numpy.ascontiguousarray, norm=numpy.linalg.norm,
+                ):
+            """
+            Takes a list of systems and returns their distances from this system.
+            """
+            return numpy.linalg.norm(
+                ary([s.pos for s in iterable]) - self.pos,
+                ord=2, axis=1.
+            )
+
     def getStation(self, stationName):
         """
         Quick case-insensitive lookup of a station name within the