PHP would very likely be better, just because it's simpler and more flexible. JSP (and other Java solutions) are somewhat useful if you're doing a lot of integration with Java or XML. If you know any Python, Django is a great choice, and for Ruby there's Ruby on Rails.
JSP requires a lot more work to get started so it's not so well suited to small project. Actually, it's not particularly suited for a large project either -- a MVC framework like Struts would probably work better in that case, if you're dead set on using Java. For PHP, you'll probably want to use a templating system like Smarty for larger projects to keep the code and HTML separated.
Experience: About three weeks of writing JSP for a class -- it's much more annoying to work with than PHP.