Be careful with the water in the meerschaum...it is after all just a form of chalk. Above all else, don't soak it in water and then smoke it. Bad bad bad. Oh the humanity!
And don't use alcohol based pipe cleaning liquids on meerschaums. They are extremely porous (that's why they smoke cool and dry) and will soak up the flavor. If you do have to clean a meerschaum with alcohol, do it with a good strong scotch that you like drinking, because your pipe will taste like that for a few weeks.
And Bill, you don't actually have to rotate pipes if you don't want to, or are too lazy. All you really need to do, provided it's a decent quality pipe, is make sure the briar is completely cool from your last smoke, and has been cleaned before your next smoke. Depending on your climate, 1-3 hours is enough. One way to get over the annoying hurdle of breaking in a nice new pipe is to smoke 3 times a day for 4-5 days, it allows you to start enjoying the pipe a lot sooner, and get over buyer's remorse more quickly. Clean your pipe not immediately, but very shortly after you dump the ash...make sure the briar is not shocked by cold after you have smoked it, but don't let the oils congeal and cool before you clean it.
The only really imperative reason to rotate pipes is to smoke different tobaccos...if you smoke one pipe with several tobaccos, every smoke will just taste like a mishmash of everything, a little bit like if you were to blend your favorite meal in a food processor.
And by the way, don't ever buy a pipe based on an idea that you will replace the stem. Unless it is a relatively low quality mass manufacture pipe, it can get tricky to replace those things properly. In addition to the usual agenda with the bowl, etc., make sure the stem has no cracks, fits firmly but not tightly, and has minimal tartar buildup. Resin, amber and SOME very high quality vulcanized rubbers can last a long time, plastic is usually a complete waste of time. However, plastic replacements are the most readily available, but if you've ever smoked one for a while, it isn't worth it.
And Shutterflower, sorry but I'll pass...I have a couple meerschaums, and that's enough. One of these days I'll get around to buying a nice Danish freehand, perhaps you'll be selling one here even.