I recently got the make: it robotics starter kit but I was wondering it there any other things I can create with the starter kit only and maybe a few extra parts? The two robots are kind of boring now. I have provided the Radio Shack link so you can see the parts it comes with!
The Kit: http://www.radioshack.com/product/index.jsp?productId=24431276
Other possibilities.
Add sensors for line following and mabye learn to build a maze solver, or, add infrared/ultrasonic to solve mazes without lines. Look through the challenges and see if any tickle your fancy to attempt to complete.
Your kit seems to be basically a base to build upon. That said adding a few inexpensive sensors and a boatload of programming will give you a vast number of possibilities. You could even add encoders and a way to actuate a pen/marker to make a drawing robot. Drawing or not, encoders could be a good plan to consider especially quadrature encoders.