First, the good news. As it turns out, every outlet in a bathroom does not need to be a 10$ GFCI outlet. A modern GFCI outlet like the 10$ ones I bough from Home Depot allow you to chain a whole string of Electrical Outlets off of a single GFCI switch... Sure, if you drop a hair-dreyer in the tub you need to search around the house to find the master GFCI switch to bring the circuit back to life, but it is perfectly safe. (The first outlet on my chain just so happened to be int he lower bathroom. From there it went to the master bathroom followed by the guest bathroom. For now, i'm just goign to have the one outlet int he guest bathroom protect the whole string of outlets... I don't own any electrical bathroom appliances anyhow.
Then, the bad news (for my wallet). Brendan pointed out that Home Depot sells some really sweet dimmer modules that work in multi-switch situations (replacing up to 8 outlets that would have otherwise been 3-way and 4-way switches.)
I decided that dimming was in fact critical for several of the zones in my house (to save power and to look less starkly lit.). As such, one of the 5$ 3-way switches would have to be replaced with a dimming 3-way switch such as this model by lutron.


Left: Lutron's cheaper Diva 3-way dimmer. Right: The master unit of the Maestro Series. (The LED's indicate the current brightness and you can dim the lights from the remote locations too.)
At 40$ + 12$ + 5$, I decided to go hog wild and get the primo Lutron setup, the Maestro series. I got a 2-pack (master + remote) for 50$ at home depot and I cannabalized a second 2-pack to get the second remote. This solved the situation and the results were fantastic. The lights can be dimmed at any location, they remember your dimmer setting and they fade ever so smoothly on and off when you tap the light switch. Was it worth 200$ to replace three zones and an extra regular dimmer with these fancy switches? Maybe not for resale value, but I sure like them.
Sadly, the included info from Lutron fails to explain how to wire more than two switches. Fortunately, the directions are available online.
For an overview of the traditional 3-way and 4-way switch wiring try this article on electrical-online.com.