Some more Peer review approaches are,
Pair Programming – In Pair Programming, two developers work together on the same program at a single workstation and continuously reviewing their work.
Peer Deskcheck – In Peer Deskcheck only one person besides the author examines the work product. It is an informal review, where the reviewer can use defect checklists and some analysis methods to increase the effectiveness.
Passaround – It is a multiple, concurrent peer deskcheck where several people are invited to provide comments on the product.

