diff --git a/treegrid.js b/treegrid.js
index c3b35a0..f7ba1c2 100644
--- a/treegrid.js
+++ b/treegrid.js
@@ -14,6 +14,7 @@
  * renderer = function(node) { return [ { innerHTML, style, className, title }, ... ] }
  *
  * items: [ node={
+ *   key: <unique key of this node across siblings>,
  *   children: [ node... ],
  *   leaf: true/false,
  *   collapsed: true/false,
@@ -351,6 +352,7 @@ function TreeGridNode(node, grid, level, insertBefore, startHidden)
 {
     this.grid = grid;
     this.level = level;
+    this.key = node.key;
     this.data = node.data;
     if (this.level === undefined)
         this.level = -1;
@@ -369,9 +371,23 @@ function TreeGridNode(node, grid, level, insertBefore, startHidden)
         insertBefore ? grid.tbody.insertBefore(this.tr, insertBefore) : grid.tbody.appendChild(this.tr);
     }
     this.children = [];
+    this.childrenByKey = {};
     if (node.children)
+    {
         for (var i = 0; i < node.children.length; i++)
-            this.children.push(new TreeGridNode(node.children[i], grid, this.level+1, insertBefore, this.collapsed));
+        {
+            var child = new TreeGridNode(node.children[i], grid, this.level+1, insertBefore, this.collapsed);
+            child._index = i;
+            this.children.push(child);
+            if (child.key)
+                this.childrenByKey[child.key] = child;
+        }
+    }
+}
+
+TreeGridNode.prototype.getChildByKey = function(key)
+{
+    return this.childrenByKey[key];
 }
 
 TreeGridNode.prototype._addCollapser = function()
@@ -507,11 +523,12 @@ TreeGridNode.prototype.setChildren = function(isLeaf, newChildren)
     }
     this.leaf = isLeaf;
     this.children = [];
+    this.childrenByKey = {};
     this.addChildren(newChildren);
 }
 
-// experimental
-TreeGridNode.prototype.syncChildren = function()
+// experimental & broken
+TreeGridNode.prototype._syncChildren = function()
 {
     var i, j;
     for (var i = 0; i < this.children.length; i++)
@@ -574,13 +591,24 @@ TreeGridNode.prototype.syncChildren = function()
     }
 }
 
-TreeGridNode.prototype.removeChild = function(i)
+TreeGridNode.prototype.removeChild = function(nodeOrIndex)
 {
-    if (!this.children[i])
-        return null;
-    var e = this.children[i].tr;
-    var l = this.children[i].level;
-    this.children.splice(i, 1);
+    if (nodeOrIndex instanceof TreeGridNode)
+    {
+        if (this.children[nodeOrIndex._index] == nodeOrIndex)
+            nodeOrIndex = nodeOrIndex._index;
+        else
+            return false;
+    }
+    if (!this.children[nodeOrIndex])
+        return false;
+    var e = this.children[nodeOrIndex].tr;
+    var l = this.children[nodeOrIndex].level;
+    if (this.children[nodeOrIndex].key)
+        delete this.childrenByKey[this.children[nodeOrIndex].key];
+    this.children.splice(nodeOrIndex, 1);
+    for (var i = nodeOrIndex; i < this.children.length; i++)
+        this.children[i]._index--;
     var k;
     do
     {
@@ -588,6 +616,7 @@ TreeGridNode.prototype.removeChild = function(i)
         e = e.nextSibling;
         k.parentNode.removeChild(k);
     } while (e && e._node.level > l);
+    return true;
 }
 
 TreeGridNode.prototype.addChildren = function(nodes, insertBefore)
@@ -607,6 +636,14 @@ TreeGridNode.prototype.addChildren = function(nodes, insertBefore)
     else
         e = this.children[insertBefore].tr;
     for (var i = 0; i < nodes.length; i++)
-        this.children.splice(insertBefore+i, 0, new TreeGridNode(nodes[i], this.grid, this.level+1, e, this.collapsed));
+    {
+        var child = new TreeGridNode(nodes[i], this.grid, this.level+1, e, this.collapsed);
+        child._index = insertBefore+i;
+        this.children.splice(insertBefore+i, 0, child);
+        if (child.key)
+            this.childrenByKey[child.key] = child;
+    }
+    for (var i = insertBefore+nodes.length; i < this.children.length; i++)
+        this.children[i]._index += nodes.length;
     return this.children.slice(insertBefore, nodes.length);
 }