acceptable to list current position on resume as "undisclosed company" ?

the way the economy is these days and the fact that it was not easy
for me to find my current job, I was wondering if people think it is
acceptable to list my current company as "undisclosed corporation" or
something like that on my resume. I am not sure exactly why I feel
like doing that, but it may prevents recruiters or others from trying
to fill my job before I have found another job or that sort of thing.
I guess I just am not sure that I want to advertise that I work for
this company and I am thinking of leaving ..

I do Ruby development ..

Well if any of the recent rails / ruby events I've been to are
representative of the overall mood, employers are falling over
themselves to find good rails developers.

If you were sending in a resume as part of a job application and I was
on the other end of that I'd think it was very odd that you hadn't
listed your current employer. You're only advertising if your
broadcasting this information generally, but so many people do that
anyway (the whole of linked-in is predicated on this) that it feeds
like a non issue