Part 1 Part 2 Part 3
Also, the best original source blogs I have found on this issue are Laura Rozen's War and Piece, and Josh Marshall's Talking Points Memo. These two have been working on the Niger story for years.
For a shorter version, The Left Coaster (eRiposte) has had two great posts going into the details of all of this.
Part 1 Part 2
I defer to these people on this topic because I think it's so very important, I don't want to muddy it up.
And no, I'm not wearing my tinfoil hat. This is damn serious. This is about an intel operation conducted to deceive my country into an unneccesary war in which tens of thousands have died. If Americans were involved in this, their actions are treason.
So, do the reading, do the homework. It's important.