AppEngine - Guestbook sample

https://developers.google.com/cloud-sql/docs/developers_guide_java#using_the_java_development_server

GWT - Php support

For PHP developer want to use appengine, try this out.

http://www.webdigi.co.uk/blog/2009/run-php-on-the-google-app-engine/

GWT - Login Manager

Just a recording refernce yet. Sorry I cant get one yet. :(

http://code.google.com/webtoolkit/tools/gwtdesigner/tutorials/loginmanager.html
http://www.dariusz-borowski.com/wp/?p=20
http://www.vogella.de/articles/GWT/article.html

GWT - How to build multiple or another page.

As a beginner in playing GWT. I don't know to create another page after I done the Getting Stated on GWT documention.
GWT Getting start

While looking on the to this stuff, I found that there was no mutiple page on GWT instead it use widget to display another view on you page.

Read the Alen Post here GWT Concepts No Multiple Pages

Reference:
Here another reference http://colchambers.blogspot.com/2010/08/creating-multiple-page-gwt-app.html