Snape's role in the Order

[kellymcj2000]

No: HPFGUIDX 71626

SO, what are people's thoughts on what Snape is doing for the Order?  
I'm guessing he's not spying on LV or if he is he's also doing 
something else.  

Harry says it's Snape's job to find out what LV is saying to the DEs 
and then there was a 
"curious, almost satisfied expression on Snape's face when he 
answered. 'Yes Potter,' he said, his eyes glinting.  'That is my 
job." Page 591, Scholastic. 
Well, we all know Snape.  If he's looking almost satisfied somebody, 
usually Harry, must have messed up.  He's probably thinking "That's 
right.  Let your arrogance lead you astray yet again Potter."  

Could be Snape is glad to let Harry think that's his job precisely 
because it isn't.  But what would it be then?  I think maybe his 
potion making abilities have something to do with his job for the 
Order.  Don't know how though.  Does anyone have any theories on his 
part in the Order?

KelMc