Keywords in URLs - any best practices? 7th September 2011 11:01 PM
“Well I never, didn't know that 
We use underscores in our URL extensions, so assumed you could use them in the actual URL.
Was thinking it might be visually more appealing breaking up the keywords. Is there any actual evidence that hyphens can cause problems, or is just accepted bad practice by you SEO folk?”

We use underscores in our URL extensions, so assumed you could use them in the actual URL.
Was thinking it might be visually more appealing breaking up the keywords. Is there any actual evidence that hyphens can cause problems, or is just accepted bad practice by you SEO folk?”
There is no evidence to suggest hyphens cause problems - absolutely none. My experience over the years is that they cause no problems AND (as you say) are much easier to read by humans!!!
Total myth.