zx-81 has updated his port of Stella for the GP2X handheld and since I lack a GP2X to be ale to comment on it lets head for the news now:

• Auto-fire mode, press RTrigger+X to switch it on/off, useful for games such as space invaders ! On given games, the auto fire can't be stopped, so an option to stop it, is available in the settings menu.
• RTrigger/LTrigger keys can be used in the keyboard settings menu to navigate between Normal, LTrigger and RTrigger compose mapping.
  Add several new hotkeys :
• . settings such as fps, render mode, auto fire speed can now be directly modified inside the emulator (no need to enter in the settings menu)
• . quick save / quick load current state (no need to enter in the main menu)
• Default Hotkeys can now be set in the keyboard mapping menu (useful to add hotkeys on existing/previous keyboard files)

Download from the homepage.