Using gpg on multiple systems

[Mike Touloumtzis]

On Mon, Feb 25, 2002 at 04:54:41PM +0100, Janusz A. Urbanowicz wrote:
> 
> create a 'master' key at home and make a signing subkey - this you export to
> work. It will allow you to operate like normally, but this subkey can be
> easily revoked and replaced by new one if compromised. The same for
> decrypting subkey.

I have a work mail address and a personal mail address; I want mail
sent to the work address to be encrypted to one subkey, and mail to
the personal address to be encrypted to another (this type of setup is
required by the thread's original poster due to his greater concerns
about workplace security).

When someone sends me mail, how do they choose which subkey is used?
Can I associate a subkey with an ID?  Or is using two completely
different OpenPGP keys (which I do now) the only way to get this result?

miket