This is also an option of course. there are lot's of ways you can achieve the same result. Experiment with both extruding and merging vertices and anything else you can think of. Then pick the technique that suits the problem best (stay away from booleans if you can help it, as mentioned). This is true for every aspect of CG and even in life itself...
Benny
When in doubt, delete history and freeze transformations.
My latest snake game
(Requires DirectX9 SDK and Framework)