I keep two passports; one gets stamps from interesting countries, and the other one is used for going to places where being well-travelled is considered suspici

I keep two passports; one gets stamps from interesting countries, and the other one is used for going to places where being well-travelled is considered suspicious (such as, it seems, the U.S.). Edit: To expand, in the UK it used to be as easy as writing a letter explaining why you needed a second (maybe it still is; haven't tried for a while). I've also got a third passport, from a different country, but so far not needed it.