Mr T's suggestion is a great one. I have always wondered why there are no podcasts focussing on language production, rather than listening comprehension.

Popup Chinese could exploit this niche market and I feel it would be a great sucess.

The closest product I've seen focussing on language production (other than a teacher) is Pimsleur's course (Excellent though it is, the vocabulary is limited and could be more fun to listen to)

For elementary learners, I think that there is no alternative to English to Chinese translation, but for more advanced students one could easily produce a podcast using Chinese only to make you think (and speak) in Chinese