I'm designing a show and I need to pick up conversations between actors onstage. I have more experience with recorded sounds and FX than with live sound production.

Here's the situation:

The director doesn't want to use body mics, so I mentioned floor mics and he freaked out. Does anyone have any suggestions for mics on stage that won't be extremely visible? I've thought of a few possibilities, but I don't really like them. I need a few good (and reasonably priced) options I can give to him.

Floor mics are a mixed bag when they are used on stage. Early on I learned that the hard way. The problem is actors can step and dance on them or so close to them you loose the ability to hear the actors. I think you should probably try hanging lavs from the the light grid or fly space poles what ever the theatre has. The lav wires can usually blend in. Make sure the lavs are omni-directional. If you can't go that root, I would try placing standard omni directional mics right in front of the stage on short stands. This will remove a lot of the smacking from footsteps that the floor mics could pick up through the floor. If none of that works, you can try to hide mics but that usually is a bad idea. Diminished sound quality and things getting knocked over are not a great way to make an impression. The real question here is what is going on in the show and why is the director freaking out. The answers to those questions may make a solution more obvious.