Hmm... a few fleas here and there is a lot of fleas. If I find fleas anywhere else besides on the cats or in their bedding (especially in my own bed or on my clothes), or if it's more than one odd flea on the cat, I'd take a shotgun approach and clean the entire house.
Fleas are nest pests, so first order of business is to get some large ziplock bags, and bag up where the cats like to sleep (i.e. if you have a cat bed, or bunch of blankets, etc), and stick those outside for now, you can clean it later with whatever you want (I suggest chucking it though). If you're unlucky enough, you'll see little tiny white worms on the bedding, those are the flea larvae.
Then clean the bejesus out of a small area of the house that can be isolated fom the rest, preferrably without carpet, like the bathroom. Don't be afraid to get on your hands and knees with a damp rag and wipe down everything. Also, take everything unnecessary out of the bathroom (rugs, towels, ornamets, etc), you'll want to wash these.
Then get a flea comb, a small disposable dish of water with some dishwashing soap, and a clean cat carrier, and one by one bring a cat into the bathroom and start combing off all the fleas you can get and after each pass dip the flea comb into the water. This will get the majority of the fleas off, and gives you and idea of how heavy the infection is. After the you can't find any more fleas coming off put the cat in the carrier and get the next. Put the bowl of water in a ziplock bag and chuck.
Keeping all cats in the bathroom, dust all corners, vacuum the entire house, wipe down all surfaces (especially the top of the fridge if your cats like to hang out there), vacuum your sofas, change your bedsheets, change into a fresh set of clothes, do your laundry, etc. With any luck, you should've gotten almost all the fleas. Now, as a precaution, you can use borax on the carpet, and meds on the cats. As a nice side effect, your house will be squeaky clean.
Reason it's important to clean the house like this is that you don't want any stray fleas around. All it takes is one and you'll have more in no time, and now that it's getting cooler, the fleas will slow down their cycles, and even if you use meds on the cats, if an egg happens to stick around (can stick around for months without hatching when it's cold) you'll get a viable flea (one that can lay eggs) long after the meds have wore off.
Sorry for the long drawn out post... good luck!