My employer works a lot with open source, even going as far as to fund the OS dev of a very well known database abstraction layer.
Looking back, it was not a good commercial decision - far too much cost for far too little benefit. We still have a "use OS and feed back changes" policy but new developments are almost never released openly because of logisitics and support cost that we as a small company cannot afford.
If someone such as RedHat offered to take on completed and documented projects I could convince my employer to release some rather nifty tools, but I agree with him that we can no longer afford to support anthing "given" away as we would like to.
Like many small software houses we try and keep our staff happy. To this end we encourage staff to get involved in projects that they take a fancy to. Some like myself select mainly work related projects - others have opted for fun stuff such as crossword engines etc.
This works well as we end up with happier more rounded staff who get to work with a larger community and they pick up skills they would not normally have/use withiin our day-to-day work.
I encourage staff to submit via private email - our last work originated submission led to our mail servers being hammered and a bunch of commercial indemnity requests from banks (legal reps) that would not take no for an answer. They see a company at the end of FOSS and try all sort of dirty tricks to get an "advantage".
During the Y2K fisaco, we had to bounce incoming phone calls from certain number ranges just to be able to get work done.
As I said the cost sometimes outweighs everything else.