On the whole, I agree with the reservations mentioned about using a "wholesale" directory submission service.
I doubt that you'll end up with any Google penalty, if only because many of the directories will ignore mention of your site. However, inclusion in directories that include or specialize in your line of business is valuable. You just need to find out which ones are relevant and then submit to each of them manually and over a period of time rather than all at once.
In my own case, I'm included in a fair number of Real Estate directories, but this has been managed over the last four or five years. I started with a recognition/awareness of well known ones, but I then kept my eyes open on an ongoing basis and submitted my site each time I ran into a directory I hadn't known of before.
Along the way, I've tended to use the same site description, but I've varied the anchor text somewhat, often in reflection of the category in which a link to my site is most appropriate. Sometimes, I've incurred a (modest) fee for inclusion but frequently all that's required of me is a reciprocal link, which in fact (or so I like to think) adds to my credibility (as in "if he's listed in all these places, there mist be something to it.")
But again, I wouldn't recommend a mass submission service. It isn't likely to give you a good return on the money you'll need to pay.
Duncan
