You can rent movies and television shows on iTunes, but not apps for your iPhone, iPod touch and iPad. That could change as compelling evidence surfaces just a day before Apple’s “Let’s talk iPhone” event that app rentals might be in the works.

The Tech Erra points to some code strings, uncovered by Sonny Dickson from iTunes 10.5 Beta 9, that strongly suggest such a feature could be unveiled at tomorrow’s press conference. The contents of the strings (seen below) clearly points to the app rental ability. Any rented app will be automatically removed from your devices, including your computer, after the rental period expires, one of the string reads:

This could be an interesting twist to today’s App Store rules that make a clear distinction between paid and free apps, here’s why.

The ability to rent apps for a certain period of time should strike a chord with a lot of consumers who otherwise would avoid apps which are costing more than 99 cents. The aforementioned model would theoretically allow them to use such apps for a limited period of time while supposedly paying a fraction of its full retail price. Perhaps this change is motivated by a case in South Korea where regulators forced Apple to change iTunes policy and allow refunds on app sales.