Your best bet is to make a live demo of how you are going to debug  
the application with Squeak and how painful to process is when doing  
the same with Java.

I think that Smalltalk is all about how the developer and the  
environment participate to achieve a goal and it is very difficult to  
convey that experience with articles and books. Java is so remote and  
looks like a mountain you are not allowed to climb further than its  
souvenirs shop, and you can't descent because so many people are  
rushing behind you.

Anyway, good resources are:

- http://www.lukas-renggli.ch/seaside/

A gentle introduction to the challenge of developing web application  
without a state machine.

- http://homepage.mac.com/svc/ADayAtTheBeach/

A nice article explaining the development process of a seaside-based  
calculator.

- http://lists.squeakfoundation.org/pipermail/seaside/2003-September/ 
002132.html

A comparison between a weblog tool written with seaside and Java.

- http://www.cincomsmalltalk.com/blog/blogView? 
showComments=true&entry=3261049347

A report on a keynote given by Avi a while ago.

- http://c2.com/cgi/wiki?JavaVsSmalltalk

- http://www.smalltalkchronicles.net/edition3-1/whyjava.html

> Hi,
>
> I need to explain to one of my customer why they can use Squeak
> instead of Java in a new project.
> "The project is a server based payment software."
>
> Do you have any good http pages ? So they can read and build an  
> opinion ?
>
> Best Regards
> W.
>
> P.S I want to keep my customer so please "Smalltalk religious  
> pages" ;)