We mentioned the unofficial Tram Hunter application last week, but Metlink Melbourne is also beta testing an official Android app that covers trams, trains and buses. Based on the user comments to date, the app definitely deserves its 'beta' label, but at least it's a start.
Public transport fiends in Melbourne already have the option of an iOS app, and there's a promise in the future that Google Maps will also incorporate public transport recommendations. Here's hoping the oft-discussed Sydney/Melbourne rivalry gets the options in NSW improved as well. Thanks Andrew for the pointer!
Metlink beta [Android Market]