I just don't get object snaps

 From:  niko (NICKP100)
Great product Michael...very intuitive

But coming from a rhino background I do have to say that the snapping system remains a bit of a mystery to me.
Here's my problem. I just created a U-shaped curve, and I turned points on. After I move some points around, I decide I want to move a point to be tangent with the adjecent points (the one before and the one after it). There's no way to do this, even with the object snap turned on.
How do I reference the points so that I can move my point to be tangent with those two?