Galactic Pulsar System? 
Indeed. That's why we put it on the Pioneer plaques. Although the odds are still almost infinitely higher someone from Earth in the next few centuries will step out and pick it up for recovery to go put it in the Tycho annex of the Smithsonian or something.
Also, the wayward traveler can also pick up on several other signposts to triangulate their position, such as certain energetic hypergiants and other phenomena like Cephid variables.
AZRedhawk44,
For what it's worth, your thinking of wormholes being local entry/exit ports is common, if incorrect. :)
Pick up a copy of Kip S. Thorne's "Black Holes and Time-Warps" for some fantastic, down to Earth reading on the subject.
Yah, they could pop out almost anywhere. And the Universe being 99.999999999999% empty intergalactic space, odds are one would dump you out somewhere rather devoid of anything interesting to do other than measure redshifts of other galaxies and clusters before you ran out of energy or life support.
The real problem with wormholes though, besides having no clue where one will take you is the almost astronomical amounts of energy it would take to "tweeze" one from the quantum background "fabric" or "foam" of space-time, then focus and force down it's gullet to get it to widen out to the macro scale so you could throw something in it, like a ship, . We're talking energy densities that will just as easily turn into a singularity/black hole on you. Plus, the disturbance of putting something into the wormhole will require even more insane amounts of energy to keep it open and stable.
We're talking the energy output of an entire star, maybe to open a wormhole big enough to be usable. And of course no one has any idea of how you'd manage that much energy should you be able to procure it.
Arthur C. Clarke once said that he thought Gamma Ray Bursters (gamma ray pulses we detect at intergalactic distances, even bigger than supernovae) might be evidence of really, really, really bad "industrial accidents".
