This week's book giveaway is in the Agile and Other Processes forum. We're giving away four copies of The Little Book of Impediments (e-book only) and have Tom Perry on-line! See this thread for details.
If you have a web application it is probably deployed in a Servlet Container, which will provide its own connection pool. I'd favour that over c3p0 if it is there, simple because it is one less thing to need to configure.