http://www-jpc.physics.ox.ac.uk/
They managed to do a complete x86-emulation in Java. You can even install Windoze or Linux on this thing. That means: With more performance you even could use Renoise (theoretically) 
Not a chance if even Doom looks crap (~6/8 FPS on my 2,66 quad core 
) in that emulator and that is without sound!
Really, i hope those Java folks wake up one day to realize that Java is not for emulation…
Yeah, after testing doom I realized that it is painfully slow. Is there a midlet-version of c64s.com somewhere? I wanna play the original gianna sisters and not the remixed version…
There is but you definately don’t want to know how painfully slow that one is (giana sisters is one click on the lowerleft side underneath the applet):
http://www.dreamfabric.com/c64/