What is the translation of the Latin phrase "In Ius Voco Spurious"?  I never
studied Latin, so my best effort is "No false Speech" or "No lies" or (since
this is on the wall of a small business in Texas) "No bullshit allowed". The
owner of the business said the sign was left when he moved in, and he
doesn't know what it means.

Literally, "In Ius Voco Spurius" means something like "I speak the law
to the illegitimate."

To break it down: 'ius' is a variant form of 'jus', or 'law. 'Voco'
means 'I speak'. 'Spurius' is Latin for 'person born out of wedlock'.

A more succinct (and more amusing) way to say this is "Sue the
bastards."

Here are a couple of online citations (one of which misspells
'spurius' as 'spirius', but what's a typo here or there?):

"In ius voco spurius... Sue the bastards" 

Albert Pike Demolay
http://www.albertpikedemolay.org/sricf/currentroster.html

"In Ius Voco Spirius (sue the bastards in Latin)"

Way of the Exploding Octopus Guestbook
http://www.geocities.com/SoHo/Studios/9868/geobook.html

This reminds me very much of a sign that my doctor has had in his
waiting-room for many years, with the slogan "Illegitimi Non
Carborundum" -- which is garbled Latin for "Don't Let the Bastards
Grind You Down." More on that phrase may be found here:

Santa Cruz Public Library
http://www.santacruzpl.org/readyref/files/a-b/bastard.shtml

My search strategy started with my rather rusty knowledge of Latin. I
then proceeded to search the Web for backup:

Google Web Search: "in ius voco"
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=%22in+ius+voco

Thanks for asking an amusing question. If anything I've said is
unclear or incomplete, or if any of the links do not function, please
request clarification; I'll be glad to offer further assistance.

Die dulci freure (Have a nice day)!

~pinkfreud