If you got rid of kanji, how many cubic miles of landfill would be needed to replace all the signs in Tokyo?
Also, the idea of spacing in a language is more varied than I ever imagined before reading these Wikipedia articles.
http://en.wikipedia.org/wiki/Space_%28punctuation%29
http://en.wikipedia.org/wiki/Interword_separation
The Japanese way of writing without spaces is known as scripta continua to people who know what they're talking about. Use this term to sound smart when talking about the kanji problem.
It seems that ancient Latin and Greek used to be written this way too. And lots of sentences ended in est as a copula, the way desu does now. Hmmm, I wonder.