In the lab, Walter makes a snack consisting of white bread, butter and sprinkles. This is known as Fairy Bread, a common children's treat in Australia which is where John Noble is from.
The glyphs for this episode spell out: UNITE
The brain activity readout on the computer screen has "Mr. X" as September's name.
The Sixth Amendment of the US Constitution is, among other things, the right to an attorney.