Here are some links to HMM related pages:

HMM Software:

Myers' Hidden Markov Model Software

Introduction to HMMs in general:

Hidden Markov Models: Adapted from Rabiner & Juang 1986

Applications of HMMs:

Audiovisual Sensory Integration Using Hidden Markov Models

Hidden Markov Models for Interactive Learning of Hand Gestures

Face Recognition Using Hidden Markov Models (Abstract only)