As of now the iPod Touch and iPhone do not support Java, but in the near future that might change. An official from Sun Microsystems said he believes that Java is going to be ported to these devices.

Java Phone

He said that Apple is planning to release a SDK for these devices in early 2008 (February), which would then result in Java ME (the open source version of Java) to be created for the device.

This could also mean more plug-ins would be ported to the device when the SDK is released. This could potentially lead to a flash player for safari. All of these updates would make the iPod Touch and iPhone better and more functional.

iPhone is getting Java Support
[Via iPhoneWorld.Ca]