Over the years, I have given presentations and workshops on a range of topics, including information architecture, interaction design, user-centred design, and visual perception and attention. Most of my talks are available at Speaker Deck.
Here are a few examples:

One of my more popular talks - given here at the Auckland Web Meetup.

A fun but nerve-wracking talk I gave at the Orcon Great Blend - pecha-kucha style (20 slides in 6 minutes), outlining the way in which humans are definitely not rational.

A talk I gave to students of the University of Auckland's business school.

A talk I gave to the students of the University of Auckland's Business School.

One of the first talk I gave at the inaugural meeting of the Auckland branch of the Usability Professional Association.

A talk I gave to the educational conference Educause about the redevelopment of the University of Auckland's staff intranet.

A talk I gave to the Auckland branch of the Usability Professionals Association about the development of a new information architecture for the University of Auckland's staff intranet.

A talk I gave to the Wellington Web Standards group .

A talk I gave to the graduate employees of a software development firm.