Here are some links to information about using Model-View-Presenter (MVP) for ASP.NET development.
First some general information from Martin Fowler: the rationale behind GUI architectures such as MVP, and his subsequent splitting of MVP into two patterns (Supervising Controller and Passive View).
Next, a code sample provided by Scott Cate, and summarised by David Hayden. Jeremy D. Miller also has a good post on TDD, MVP and ASP.NET, and a later post providing some additional comments. Finally, a CodeProject article by Bill McCafferty on MVP within ASP.NET 2.0.
UPDATE: Found a nice link summarising and describing the differences between Model-View-Controller (MVC) and MVP patterns.