I am currently working on a website and in some of my paragraphs there seems to be two spaces between some words when there really isnt.

see: http://advertel.com/newsletter/JanFeb08/index.html

Second paragraph: "an entirely new audience to your ADS-ON-HOLD® messages."

Any ideas on how to fix this?

When you justify text and have a comparatively narrow block there isn't much room to spread the text evenly so you end up with varying spaces between words.

Just what Alan said. You either need to use something other than justify on the text or you need to add or remove the occasional word from a paragraph to fix the spacing.