How should I handle media with my app?

I have an application that uses media and I am not sure where I should store it. Images and video would be tied in with other information, I suppose similar to a contact list with images, and I could imagine a lot of media having to be used with the application. Would storing the images and video on the phone, sd card, or within the application in a database or something be best? What is common practice and what have some of you guys been doing with this?

thank you