[arivero]

This pdf launchs xterm and xclock when used in an standard unix machine under xpdf (it asks for confirmation, do not worry). Try it to see if it opens the confirmation dialog. Just open it and click one of the links. The first one is an standard URL link, the two other are /Launch actions.

UPDATED: I have put some other links to experiment parameters, and attached the tex source. Note that it is to be created with pdftex, not with plain tex.