how many squares are there across a scrabble board? i should think this would be the only limit to a word's length.

Depends on your rules, the latest Disney commercial I've seen has a family playing scrabble and the youngest is allowed to go any direction she wants, plays supercalifragilisticexpialadocious (yes, I know it's spelled wrong it won't go through the spell checker, my third grade teacher would be so sad. I had to write that word thousands of times for punishment in that class, he probably thought it was the only thing I learned from him, and I didn't.)