It should work on iPod Touch ...

it should work on iPod Touch

Hi, rudvalis.
So far iPad (iTablet) is just a big iPod/iPhone. It runs iPhone OS 3.2. So unfortunately no Java. Even if you jailbreak you will just get unofficial Java without Safari support.
Sorry about that. I'll try to explain in detail.
There is no Java for iPhone as it is on a desktop or many other phones. Apple doesn't want Java to be on the iPhone.
Saurik made a project to port Java to the iPhone. For now you can use Java with many many limitations. You cannot just run regular java application, you cannot use java in Safari.
The site you mention uses my marerial to make users sign up on a poker site through banner links. Users click on links (banners), sign up and that site gets a lot of money. The bad thing about all this is that you cannot play java poker on the iPhone.
There is no support fo Java applets, only command line java and gui via jocstrap libraries.
Unfortunately, there is no support of awt or swing.
2ollie: no you will not be able to run regular jar monile app. There is support only for command line and user interface through special libs (jocstrap). The application has to be written on Java specially for iPhone