According to Wikipedia Sanda and San Shou are simply alternate spellings for the same style, but of course _ing _un has taught us that while one spelling of a style may have lots of terrible videos, whichever spelling YOU do is much better.

Any San Shou or Sanda practicioners care to clear this up?

I've always thought that they were different names for the same thing

In the case of San shou/Sanda, I can quite safely assure you those two things mean the exact same thing. They are more or less interchangeable terms.
Sanda Fighter, San shou Fighter.
Sanda Competition, San shou competition.

The National Wushu Federation over here doesn't make a fuss about the terms.

I believe at one time Sanshou referred to the actual training of techniques for competition or use in the ring, whereas Sanda referred to actually fighting in the ring. But today they are used interchangeably.

Sanda means loose/free fight.
Sanshou means loose/free hands.
The first word indicates that they allow the same rules and range.

Excellent, thanks for the info.

sanda means muay thai of china, whereas sanshou means thai boxing of china.

Your chinese is suspect. I'm fairly certain it is the otehr way around.

Stop confusing me you two, I liked it when everyone said they were interchangeable and that's that. Yer book-larnin' and school-words hain't gon' make no chinaman a' me.

They are interchangeable,

But Sanda tends to be used when knees and elbows are allowed, and San Shou when no knees etc are allowed.