I thought this might be a helpful topic. I'm no expert on this, as I've only been in one of these rooms. This will be a woefully incomplete list until other guys contrubute.

Soi Cowboy: Both Dollhouse and Deja Vu have on-premises rooms. Given the layout, I suspect that Shark might have a room, too, but I'm not really sure.

Soi 33: None that I know of, but Napoleon does have a rarely occupied serviced apartment (The Ritz Apartments) right upstairs that can be used as such.

NaNa: I'm not aware of any, but it's hard to believe that one of the lady boy bars doesn't have something to keep punters from making a walk of shame.

Queen's Park Plaza Soi 22: No in-house rooms. Late at night, you might be able to do someone in the bathroom. But, then again, only about 5 of the 33 bars in this complex have their own bathroom. To my knowledge, the can at my bar has not been used for such purposes...unless it was used by an extremely premature ejaculator.

Washington Square: The Silver Dollar has rooms upstairs. I would guess that at least one or two other bars in this area have a similar setup.

Patpong: Super Queen on Patpong II has one room. The facilities are primitive (i.e. no shower and you actually see the open closet where the dancers' street clothes hang). But, the aircon works, there's constant dim lighting and the bed's fairly big. The walls are so thin that you can hear the music from the bar pumping at damn-near full volume. This could be good or bad, depending on your personal preference. I kinda dug it (as you can guess, this is the one room I've actually been in).

Hopefully some of you guys can add to the list or give some more details about the rooms that I know about, but haven't used.

Manos.

Actually there's a short time hotel in Nana Plaza on the upper level on the left as you go in (you can take the elevator there up, walk around to your right and it's then on your left hand side). It's been awhile since I've used it (courtesy of a couple of Dave the Rave's beauties in Angelwitch), but has come in handy when I was looking for some extracurricular activity from the gf I had back at my Bangkok apartment.

There are at least two short-time hotels in NaNa Plaza. I was trying to suss out which bars in Bangkok have rooms within the four walls of the bar, ala pretty much every bar on soi 6 in Pattaya.

Manos.

Soi Cowboy;
There is a short time room at the Baccarat club. how i know this? well, I've used it twice and the room is quite big. is all the way to the top and it has a window, which stay closed all the time. if you opened it a bit you can see the neon sign of the club, I did it just for curiosity. anyways, is ok and the lighting is low so pretty good for the "action". ///