Question

Spearmint????   I was told this is spearmint, but it doesn't look like Spearmint too me when I looked at a friends plant. I've been eating this plant cause I was told it was spearmint, I could be slowly killing myself.

Answer
It is hard to be sure from the picture but it looks more like Catmint to me. Here is one photo http://www.birdsandblooms.com/Gardening/Summer/Catmint/
Photo and information on the edibility of catmint http://www.examiner.com/article/name-this-plant-win-one-for-your-garden  and more info http://blacktoadherbals.com/blog/?tag=catmint

Let me know if it looks like Catmint to you.  
Plants in the mint family have square stems - so if you cut a cross section of the stem it would be square.  You can usually feel with your fingers and tell it is square.  Catmint is in the mint family.

Information about using Catmint:
http://www.botanical.com/botanical/mgmh/c/catmin36.html
http://www.ageless.co.za/herb-catmint.htm