diff --git a/ethchain/state_manager.go b/ethchain/state_manager.go
index 29c3cd16b..1ab58386a 100644
--- a/ethchain/state_manager.go
+++ b/ethchain/state_manager.go
@@ -50,6 +50,10 @@ type StateManager struct {
 	// Comparative state it used for comparing and validating end
 	// results
 	compState *State
+
+	// It's generally know that a map is faster for small lookups than arrays
+	// we'll eventually have to make a decision if the map grows too large
+	watchedAddresses map[string]bool
 }
 
 func NewStateManager(ethereum EthManager) *StateManager {
@@ -60,6 +64,7 @@ func NewStateManager(ethereum EthManager) *StateManager {
 		Ethereum:         ethereum,
 		stateObjectCache: NewStateObjectCache(),
 		bc:               ethereum.BlockChain(),
+		watchedAddresses: make(map[string]bool),
 	}
 	sm.procState = ethereum.BlockChain().CurrentBlock.State()
 	return sm
@@ -309,18 +314,9 @@ func (sm *StateManager) Stop() {
 }
 
 func (sm *StateManager) EvalScript(script []byte, object *StateObject, tx *Transaction, block *Block) {
-	// Recovering function in case the VM had any errors
-	/*
-		defer func() {
-			if r := recover(); r != nil {
-				fmt.Println("Recovered from VM execution with err =", r)
-			}
-		}()
-	*/
-
 	caller := sm.procState.GetAccount(tx.Sender())
 	closure := NewClosure(caller, object, script, sm.procState, tx.Gas, tx.GasPrice, tx.Value)
-	vm := NewVm(sm.procState, RuntimeVars{
+	vm := NewVm(sm.procState, sm, RuntimeVars{
 		Origin:      caller.Address(),
 		BlockNumber: block.BlockInfo().Number,
 		PrevHash:    block.PrevHash,
@@ -333,5 +329,22 @@ func (sm *StateManager) EvalScript(script []byte, object *StateObject, tx *Trans
 
 	// Update the account (refunds)
 	sm.procState.UpdateStateObject(caller)
+	sm.Changed(caller)
 	sm.procState.UpdateStateObject(object)
+	sm.Changed(object)
+}
+
+// Watch a specific address
+func (sm *StateManager) Watch(addr []byte) {
+	if !sm.watchedAddresses[string(addr)] {
+		sm.watchedAddresses[string(addr)] = true
+	}
+}
+
+// The following objects are used when changing a value and using the "watched" attribute
+// to determine whether the reactor should be used to notify any subscribers on the address
+func (sm *StateManager) Changed(stateObject *StateObject) {
+	if sm.watchedAddresses[string(stateObject.Address())] {
+		sm.Ethereum.Reactor().Post("addressChanged", stateObject)
+	}
 }
diff --git a/ethchain/state_object.go b/ethchain/state_object.go
index f562e5b04..8d86ef44e 100644
--- a/ethchain/state_object.go
+++ b/ethchain/state_object.go
@@ -18,6 +18,28 @@ type StateObject struct {
 	initScript []byte
 }
 
+// Converts an transaction in to a state object
+func MakeContract(tx *Transaction, state *State) *StateObject {
+	// Create contract if there's no recipient
+	if tx.IsContract() {
+		// FIXME
+		addr := tx.Hash()[12:]
+
+		value := tx.Value
+		contract := NewContract(addr, value, []byte(""))
+		state.UpdateStateObject(contract)
+
+		contract.script = tx.Data
+		contract.initScript = tx.Init
+
+		state.UpdateStateObject(contract)
+
+		return contract
+	}
+
+	return nil
+}
+
 func NewContract(address []byte, Amount *big.Int, root []byte) *StateObject {
 	contract := &StateObject{address: address, Amount: Amount, Nonce: 0}
 	contract.state = NewState(ethutil.NewTrie(ethutil.Config.Db, string(root)))
@@ -39,6 +61,10 @@ func NewStateObjectFromBytes(address, data []byte) *StateObject {
 	return object
 }
 
+func (c *StateObject) State() *State {
+	return c.state
+}
+
 func (c *StateObject) Addr(addr []byte) *ethutil.Value {
 	return ethutil.NewValueFromBytes([]byte(c.state.trie.Get(string(addr))))
 }
@@ -47,8 +73,10 @@ func (c *StateObject) SetAddr(addr []byte, value interface{}) {
 	c.state.trie.Update(string(addr), string(ethutil.NewValue(value).Encode()))
 }
 
-func (c *StateObject) State() *State {
-	return c.state
+func (c *StateObject) SetMem(num *big.Int, val *ethutil.Value) {
+	addr := ethutil.BigToBytes(num, 256)
+	c.SetAddr(addr, val)
+	//c.state.trie.Update(string(addr), string(val.Encode()))
 }
 
 func (c *StateObject) GetMem(num *big.Int) *ethutil.Value {
@@ -65,11 +93,6 @@ func (c *StateObject) GetInstr(pc *big.Int) *ethutil.Value {
 	return ethutil.NewValueFromBytes([]byte{c.script[pc.Int64()]})
 }
 
-func (c *StateObject) SetMem(num *big.Int, val *ethutil.Value) {
-	addr := ethutil.BigToBytes(num, 256)
-	c.state.trie.Update(string(addr), string(val.Encode()))
-}
-
 // Return the gas back to the origin. Used by the Virtual machine or Closures
 func (c *StateObject) ReturnGas(gas, price *big.Int, state *State) {
 	remainder := new(big.Int).Mul(gas, price)
@@ -77,11 +100,15 @@ func (c *StateObject) ReturnGas(gas, price *big.Int, state *State) {
 }
 
 func (c *StateObject) AddAmount(amount *big.Int) {
-	c.Amount.Add(c.Amount, amount)
+	c.SetAmount(new(big.Int).Add(c.Amount, amount))
 }
 
 func (c *StateObject) SubAmount(amount *big.Int) {
-	c.Amount.Sub(c.Amount, amount)
+	c.SetAmount(new(big.Int).Sub(c.Amount, amount))
+}
+
+func (c *StateObject) SetAmount(amount *big.Int) {
+	c.Amount = amount
 }
 
 func (c *StateObject) ConvertGas(gas, price *big.Int) error {
@@ -130,28 +157,6 @@ func (c *StateObject) RlpDecode(data []byte) {
 	c.script = decoder.Get(3).Bytes()
 }
 
-// Converts an transaction in to a state object
-func MakeContract(tx *Transaction, state *State) *StateObject {
-	// Create contract if there's no recipient
-	if tx.IsContract() {
-		// FIXME
-		addr := tx.Hash()[12:]
-
-		value := tx.Value
-		contract := NewContract(addr, value, []byte(""))
-		state.UpdateStateObject(contract)
-
-		contract.script = tx.Data
-		contract.initScript = tx.Init
-
-		state.UpdateStateObject(contract)
-
-		return contract
-	}
-
-	return nil
-}
-
 // The cached state and state object cache are helpers which will give you somewhat
 // control over the nonce. When creating new transactions you're interested in the 'next'
 // nonce rather than the current nonce. This to avoid creating invalid-nonce transactions.
diff --git a/ethchain/vm.go b/ethchain/vm.go
index bc4c65d03..93557007d 100644
--- a/ethchain/vm.go
+++ b/ethchain/vm.go
@@ -30,6 +30,8 @@ type Vm struct {
 	vars RuntimeVars
 
 	state *State
+
+	stateManager *StateManager
 }
 
 type RuntimeVars struct {
@@ -42,8 +44,8 @@ type RuntimeVars struct {
 	TxData      []string
 }
 
-func NewVm(state *State, vars RuntimeVars) *Vm {
-	return &Vm{vars: vars, state: state}
+func NewVm(state *State, stateManager *StateManager, vars RuntimeVars) *Vm {
+	return &Vm{vars: vars, state: state, stateManager: stateManager}
 }
 
 var Pow256 = ethutil.BigPow(2, 256)
diff --git a/ethutil/value.go b/ethutil/value.go
index 04131aba9..b7756f9b1 100644
--- a/ethutil/value.go
+++ b/ethutil/value.go
@@ -20,7 +20,12 @@ func (val *Value) String() string {
 }
 
 func NewValue(val interface{}) *Value {
-	return &Value{Val: val}
+	t := val
+	if v, ok := val.(*Value); ok {
+		t = v.Val
+	}
+
+	return &Value{Val: t}
 }
 
 func (val *Value) Type() reflect.Kind {