I am not Ben but....

There are adapters that you can purchase or sometimes they come with microphones that adapt the 3/8-16 thread to the 5/8-27 threads that you need for your microphone clips.

I have a small lathe and have made some adapters for myself for the light stands that do not have any threads on them. I just picked up two really really nice BOGEN light stands for $9.99 each at the local industrial surplus store and they had 1/4-20 threads on them plus an adapter that was very very nice for tilting the heads.

There are lots of places that have very neat clamps for microphones that also have stand adapters. This is one place http://www.sabrasom.com.br/
and also these can come in very handy http://www.markertek.com/Product.asp?baseItem=MAC%2D1&cat=AUDIOEQUIP&subcat=MICACCESSR&prodClass=MICADAPT&mfg=Atlas+Soundolier&search=0&off=

and I use these people http://www.micsupply.com/standaccessories.htm

This is a good idea http://www.micsupply.com/km240.htm

and

http://www.micsupply.com/standaccessories.htm look here on this page
Stand fitting w/ 3/8>5/8 adapter

http://www.equipmentemporium.com/MicSupport.htm also has some nice items as well

Novel and cheap http://www.podcastingnews.com/items/On-Stage/MUPKSA7575.htm

The standard thread size for music mic stands is 5/8-27.
The standard thread size for fishpoles and most shockmounts (for film/TV) is 3/8-16. Note that this is also the standard thread size for professional camera mounting.
The old Hollywood thread size for studio booms and fishpoles was 5/16-18. This size is no longer used on currently manufactured equipment, but may still be found on some older poles and shockmount handles.
The standard thread size for amateur video and 35mm still photography is 1/4-20.

Ahhh. So what you're saying is that the handfuls of female 3/8" to male 5/8 27 adapters that I have (from various microphone purchases) have the same thread as the 3/8" threads in the photo industry? If so, I would have all the adapters I need. That would be fantastic.

Thanks for the excellent info.

Yup... I either use the little screw on adapters to get to the 3/8" thread or Bogen/Manfroto makes a attachment that goes over the top of a light stand and ends in a 3/8" thread.

--Ben