Da-da da-da da-da da-da, da-da da-da da-da da-da, Breadman!
Good answers above, but as a baker by trade and a brewer by passion, I do have some thoughts. Baker's yeast and brewer's yeast (though not lager yeast) are selected strains of the same species, S. cerevesiae. There are several strains of wet and dry baker's yeast that behave a bit differently in their rehydration needs and speed of fermentation, but all originate from brewer's yeast. They all have been selected for quicker fermentation than brewer's yeast in a dough medium.
Brewer's yeast certainly does work in bread, but my experience is that it is slower. It helps to wash it to avoid bitterness, and you need to use more. One difference between beer and bread is that with bread, you want the other micro-organisms to to grow along with the yeast for a more complex flavor, so using less yeast and letting it take its time makes better bread. With beer, of course, you don't want those other critters at all.
It's been a while since I baked with harvested brewer's yeast, but my recollection is that it made a bread with a somewhat fruity flavor and aroma.
I suspect that some brewer's would work better than others. My guess is that a good, top-cropped yeast like my favorite, WLP022 (which I myself brought back from Ridley's Brewery and supplied to Chris White) might be a good choice as it's easy to collect lots of clean yeast from the top.
I also fermented beer many years ago with wet baker's yeast, and I don't recommend this. It had a definite phenolic, "wild yeast" flavor. I suspect that it has the same gene as Bavarian weizen and some Belgian yeasts, and which has been selected against in most cleaner brewer's yeast. But I wanted to replicate the old prohibition recipe - can of hopped malt extract, five pounds of sugar, hot water to five gallons in a stoneware crock. Float a cake of yeast on a slice of rye toast and as the toast disintegrates, the wort cools and the yeast diffuses into the very warm wort.