I don't need any help actually finding them; I can see plenty. But are there any you can actually sleep with, or interact with at all, or are they just for decoration?

If I mind right there's always 'that robot' you can utilise for that sort of thing.

go to the court yard (in Gomorrah) as you walk through a girl by Joana will talk to you, with a high Science/Medicine can't remember which one, you notice she is strung out on Med-X. you talk to her and she invites you back to her room. While speaking to her, she opens up a new mission for you, and asks what kind of payment you want in advance to do this...she stresses anything...will if you play the options right, you'll notice the ones that are the Brown-chicken-brown-cow ones, she replies "I know what you want and i know how to give it to you." you wake up with a well rest exp buff and if you have companions with you it seems odd to see them starring at you...especially ED-E...

There should be one around somewhere...Over the rainbow...Just let me search here and there for the link to see if there are any.

EDIT: http://fallout.wikia.com/wiki/Joana

High medicine/Science skill to see if she is on Med-X