There is no doubt that TMDb is great open database for developers to implement searching movies and people.
I have been web-surfing to get an idea for not commercial purpose but my mobile app portfolio . TMDb is the one of the best choice to start in order to build simple web application providing movie information mainly focused on Mobile environment.
I just submitted the request form for TMDb API key. Next three business days needs to be reviewed for process.
This is the good tutorial for starting off. (Update: API key was given about six hours later by email.)