1st off Sorry for the extra Posting Dan, I just wanted to get in a reply to Derek but wasn't getting a reply link on any of the postings after I logged in.
Now for Derek's question. Hydrogen Fuel Cells can be used to electrolyze water. But under normal operation a Fuel Cell collects energy given off by Hydrogen and Oxygen combining into Water. This Produces both electricity and heat, and yes the excess heat given off could be used for other purposes. Here is a link explaining electrolysis in more detail:
http://www.physchem.co.za/Redox/Electrolysis.htm
The way that a Fuel Cell can produce H2 (Hydrogen) and O2 (Oxygen) is when it is run in reverse. By adding electricity to a cell submerged in water it will generate H2 and O2, H2 at the cathode and O2 at the anode. (little footnote here, pure H20 doesn't conduct electricity very well so a good electrolyte like KOH (Potassium Hydroxide) or H2SO4 (Sulpheric acid) will help the energy get between the posts) Platinum is usually used because it is a good catalyst, it does not interfere with the reaction and is resistant to much of the effects of electrolysis, carbon rods can be used for the electrolysis part though)
When a Fuel cell runs normally it takes in H2 and O2 yielding H20 + O2 + electricity and heat. There are some good articles on homepower files section that go into good detail on how they are constructed.
Here is a link about Fuel cells including a small project:
http://sci-toys.com/scitoys/scitoys/echem/fuel_cell/fuel_cell.html
The long and short is yes you can make heat with fuel cells, and electricity. Sorry if I went back over stuff you already know. Its just a subject I really like. One day would love to play with some :-) I have played with an electrolysis setup in high school lab, we split water. Just haven't run it in reverse. Have fun and if you do look any deeper into fuel cells let us know, would love to hear about it :-)