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.

It is an alternative form of Testing, where some colleagues were invited to examine your work products for defects and improvement opportunities.

Some Peer review approaches are,

Inspection – It is a more systematic and rigorous type of peer review. Inspections are more effective at finding defects than are informal reviews.
           Ex : In Motorola’s Iridium project nearly 80% of the defects were detected through inspections where only 60% of the defects were detected through informal reviews.

Team Reviews – It is a planned and structured approach but less formal and less rigorous comparing to Inspections.

Walkthrough – It is an informal review because the work product’s author describes it to some colleagues and asks for suggestions. Walkthroughs are informal because they typically do not follow a defined procedure, do not specify exit criteria, require no management reporting, and generate no metrics.