Thanks for the replies everyone. I will post all of my developing ideas here.


Not too worried about this, since the server screens all the in-coming messages, and logs the potentially illegitimate requests(either a bug or malicious stuff). The only thing visible to the client is the collision information, to do client-side guessing stuff.

Does anyone know what specific knowledge I should have to create a 2d tile-based level generator, like the Diablo series? I want to use it in a networked game, so the server will generate the map using some input, such that the input can be sent to the clients and generate the same map.

Please let me know of some algorithms I can study that can open my mind in this area, and lead to the development of my own solution. Thanks in advance!

Runescape must make a small fortune. 

I know this isn't related to Java, but if you want to make mobile game targeted to the iphone/ipod touch platform, they have a very nice system for content delivery. You pay 100$ to join the developer program, and apple gets a % of your revenue. You'll have to learn objective-c though. Apple seems to be the only reasonable content provider for mobile phones.

http://developer.apple.com/iphone/program/