I'm looking for the name of a science-fiction novel/series, which I read sometime between 2001-2005. The only things I can definitely remember:
There are "pleasure bots" (there's a name for them in the book, but I forget), actually very life-like, that are stored in some sort of case when not in use. (Sort of like the ivory dittos from "Kiln People", but these are more-or-less autonomous, if a bit empty-headed.)
No one is really sure where these androids came from, but at some point in the book (or later in the series) it is revealed that they were created by a woman scientist-type (who might have been the protagonist in an earlier book in the series) for the purpose of population control, and to reduce violence against women.
I think the woman scientist is near-immortal, or can time-travel; unless I'm getting different works mixed up, this pleasure-bot scheme is one of several interventions she performs across centuries, if not millenia.