diff --git a/src/js/ripple/transaction.js b/src/js/ripple/transaction.js
index 20e016f2..1167907b 100644
--- a/src/js/ripple/transaction.js
+++ b/src/js/ripple/transaction.js
@@ -167,6 +167,9 @@ Transaction.set_clear_flags = {
   }
 };
 
+Transaction.MEMO_TYPES = {
+};
+
 Transaction.formats = require('./binformat').tx;
 
 Transaction.prototype.consts = {
@@ -595,6 +598,48 @@ Transaction.prototype.setFlags = function(flags) {
   return this;
 };
 
+/**
+ * Add a Memo to transaction. Memos can be used as key-value,
+ * using the MemoType as a key
+ *
+ * @param {String} data
+ * @param {String} type
+ */
+
+Transaction.prototype.addMemo = function(type, data) {
+  if (!/(undefined|string)/.test(typeof type)) {
+    throw new Error('MemoType must be a string');
+  }
+
+  if (!/(undefined|string)/.test(typeof data)) {
+    throw new Error('MemoData must be string');
+  }
+
+  function toHex(str) {
+    return sjcl.codec.hex.fromBits(sjcl.codec.utf8String.toBits(str));
+  };
+
+  var memo = { };
+
+  if (type) {
+    if (Transaction.MEMO_TYPES[type]) {
+      //XXX Maybe in the future we want a schema validator for
+      //memo types
+      memo.MemoType = Transaction.MEMO_TYPES[type];
+    } else {
+      memo.MemoType = toHex(type);
+    }
+  }
+
+  if (data) {
+    memo.MemoData = toHex(data);
+  }
+
+  this.tx_json.Memos = (this.tx_json.Memos || []).concat({ Memo: memo });
+
+  return this;
+};
+
 // Options:
 //  .domain()           NYI
 //  .flags()
diff --git a/test/transaction-test.js b/test/transaction-test.js
index 5c8b065d..df7aae62 100644
--- a/test/transaction-test.js
+++ b/test/transaction-test.js
@@ -292,9 +292,7 @@ describe('Transaction', function() {
     var s3 = new Server(remote, 'wss://s-west.ripple.com:443');
     s3._connected = true;
 
-    // <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
     s3._load_factor = (256 * 7) + 1;
-    // Is this ever possible? <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
 
     var s4 = new Server(remote, 'wss://s-west.ripple.com:443');
     s4._connected = true;
@@ -1017,6 +1015,53 @@ describe('Transaction', function() {
     transaction.setFlags('test');
   });
 
+  it('Add Memo', function() {
+    var transaction = new Transaction();
+    transaction.tx_json.TransactionType = 'Payment';
+
+    transaction.addMemo('testkey', 'testvalue');
+    transaction.addMemo('testkey2', 'testvalue2');
+    transaction.addMemo('testkey3');
+    transaction.addMemo(void(0), 'testvalue4');
+
+    var expected = [
+      { Memo: {
+        MemoType: new Buffer('testkey').toString('hex'),
+        MemoData: new Buffer('testvalue').toString('hex')
+      }},
+      { Memo: {
+        MemoType: new Buffer('testkey2').toString('hex'),
+        MemoData: new Buffer('testvalue2').toString('hex')
+      }},
+      { Memo: {
+        MemoType: new Buffer('testkey3').toString('hex')
+      }},
+      { Memo: {
+        MemoData: new Buffer('testvalue4').toString('hex')
+      } }
+    ];
+
+    assert.deepEqual(transaction.tx_json.Memos, expected);
+  });
+
+  it('Add Memo - invalid MemoType', function() {
+    var transaction = new Transaction();
+    transaction.tx_json.TransactionType = 'Payment';
+
+    assert.throws(function() {
+      transaction.addMemo(1);
+    }, 'MemoType must be a string');
+  });
+
+  it('Add Memo - invalid MemoData', function() {
+    var transaction = new Transaction();
+    transaction.tx_json.TransactionType = 'Payment';
+
+    assert.throws(function() {
+      transaction.addMemo('key', 1);
+    }, 'MemoData must be a string');
+  });
+
   it('Construct AccountSet transaction', function() {
     var transaction = new Transaction().accountSet('rsLEU1TPdCJPPysqhWYw9jD97xtG5WqSJm');