Nice!
You might consider using this driver circuit.
http://www.dealextreme.com/details.dx/sku.4451



You get 5 for $8.51 with free shipping. Operates using 1 or 2 1.5 volt batteries. I would use 2 AA Ni-MH rechargeable batteries. Has 5 modes including flashing modes. You can operate one of your LED's on steady and the second in flash mode. You'll have 3 extra so you can build another blinkie for the front!