17. A speech processing method, comprising: receiving a natural language speech input representing commands and data in the form of spoken words; analyzing the speech for contextual indicia to distinguish between spoken commands instructing a device at take automated action, and spoken words intended as data; determining whether speech analyzed to comprise commands, represents a sufficiently complete command capable of at least partial execution, or whether additional command input is required; if required additional command input is not received within a contextually appropriate period, prompting the speaker for additional input to complete the command sufficient for at least partial execution; at least partially executing commands; and passing speech containing words intended as data to a data sink, wherein a command is targeted to one of a plurality of respective applications while preserving a respective prior system state, wherein at least one of: after command execution, and in dependence on a result thereof, a system state is selectively restored or processing assumed by another application without restoring the prior system state; and a command restores one of a previously preserved system state.
21. The method according to claim 17 , wherein a plurality of applications are concurrently available, and said analyzing step is performed with respect to, and directed at, a particular one of the available applications and the command is at least partially executed by that respective application.