Yes.
I use UML + PHP to develop Web applications and it's very cool.
As a UML tool I use Umbrello UML Modeller, witch you can find at http://uml.sourceforge.net/
I've also read a good book theaches you in UML and WAE, witch is the extension of the UML for the Web.
The book is Buiding Web applications with UML, there are two editions of the book
Hope that it helps
