After reading Rhen's solution to springtime fleas, I thought I'd post what worked for us.
We battled them about a month ago. My poor Troubles was the only one getting bit...but just everywhere! I began adding apple cider vinegar to the cats wet food: 1 tsp per can. That causes them to be an uninviting host, and they didn't seem to mind the new flavor.
Then I sprinkled borax on the carpet, brushed it in with the broom and kept the kids out for an hour or two. A thorough vacuuming later, no fleas! I repeated the carpet treatment the next week after any eggs hatched, and we haven't see one since. Some people use a salt and borax mix on the carpet, to dry the flea eggs and prevent any hatching, but I though the salt might damage my metal vacuum, so I refrained and repeated.