Here’s a small tip to run any JAVA games meant for 176×208 resolution mobiles on your latest S60 3rd Edtion mobile device in Full Screen (or the supported highest screen resolution for your mobile phone, for example S60 3rd Edition devices like Nokia N80 support a screen resolution of 352×416 while S60 2nd Edition device like N73 support a resolution of 240×320). Via AAS Forum.

1) Download and install WinRar
2) Goto Options—>Settings—>Integration and select Associate WinRAR with JAR
3) Now open the JAR file using WinRAR, goto META-INF folder, and extract the MANIFEST.MF file to your desktop computer
4) Open MANIFEST.MF with Notepad and add the following lines at the end

Nokia-MIDlet-Original-Display-Size: 176,208
Nokia-MIDlet-Target-Display-Size: 352,416

Original display is the dependant on the original resolution meant for the game
Target display is where you can enter your mobile device’s screen resolution.Like if you’ve got a Nokia N80, N93, etc, you can enter 352,416

5) Save the file in notepad and place it back into META-INF folder

Update: A free Windows based utility has been released that allows you to change the screen resolution to any of the following predefined formats: 176 X 208 (Basic) , 240 X 320 (QVGA) and 352 X 416 (Double)