One day while drinking a cup of coffee at work, I thought the styrofoam coffee cup might make an interesting model rocket.  That week I built the Cup of Coffee to Go and flew it the following weekend.  It flew fairly well and had the side benefit of glide recovery (sort of). 

It is easy to build.  Here are the steps:

1. Cut the bottom off of the 20 oz. Styrofoam cup
2. Using a tube marking guide, draw three lines the length of the motor tube at equal distances apart.
3. Cut three fin struts from the balsa stock.
4. Glue the fin struts to the motor tube along the lines, about 1" from the bottom of the tube.
5. Glue the launch lug along one side of the tube, next to a fin strut.
6. Glue the engine block into the top of the motor tube.
7. After the glue has dried, test fit the motor tube assembly into the cup.  The top of the motor tube should protrude at least 1/4" past the top of the cup.  Sand or add shims to the fin struts as needed to fit the motor tube assembly properly.  Finally, glue the assembly into the cup.  (Important:  the motor tube must extend at least 1/4" past the top of the cup to keep the CG far enough forward for stable flight.)

The only motor I recommend for use in the Cup of Coffee to Go is the B4-2.  Other motors do not provide as stable of a flight.  (I flew the rocket twice with B4-2 motors and once with a B6-2.  The B6-2 flight was a bit unstable.)  I've flown this rocket where the motor has ejected after burn out and where it has been retained.  In both cases, the model returned via a horizontal glide; however, the best glide results when the motor is ejected.  Have fun!