This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Presizing the StringWriter is optional, but improves performance. Here I assumed that the file encoding was one byte per character. If that's not the case you may wish to presize differently - e.g. for UTF-16 use