How to embed usability & UCD internally "offers practical advice of what a user champion can do to introduce and embed usability and user-centered design within a company" and includes 'guerrilla tactics' or small steps towards getting usability implemented. But probably the most important point is this:
The most effective method of getting user centered design in the process is through usability testing. Invite key stakeholders to watch the usability testing sessions. Usability testing is a real eye-opener and once observed most stakeholders find it difficult to ignore the user as part of the production process. (The most appropriate stakeholders are likely to be project managers, user interface designs, creative personnel, developers and business managers.)
I would have emphasised the point above even if they hadn't. The difference that usability testing makes to the attitudes of internal stakeholders is amazing and can really focus the whole project team on usability and user-centred design.