Eh...? This is a Canadian term. It is like saying, "don't you agree?" An example of how to use this Canadian word is, "Free health care is great, eh?" Eh dates back to the early days of Sumeria, and is commonly used in Occult rituals to summon beings like Satan, Bethor, FDR, and the tortured soul of Al Gore.
Modern-day usage is attributed to the creation of Happy Days where popular character Fonzi often courted agreement amongst other characters by raising his thumbs and saying "Ehhhh!"
In the 1980s, after America bestowed upon Canada the permission to create plastics, and thus unleashing mass production of televisions sets in the country, popular Canadian culture tuned in their sets and picked up on Fonzi's character. At first, young Canadian boys and girls went with "You're such a Potsi" but then came to find saying "eh" as being more phonemically economical.
Linguists in Canada have made "eh" a subject of much research and investigation in such journals as Linguistics Today, eh? and Pragmatics, eh?
It is unfortunate that Americans were not more attuned to spotting this tell-tale sign of someone who has lived in Canada. If so, perhaps those 19 terrorists of 9/11 could have been spotted and stopped after crossing the border from Canada.
Eh? can also mean several other expressions depending on placement and can even be used in similar fashion to the american counterpart " dude "