Well, you certainly can’t blame worldwide convenience chain 7-Eleven for a lack of creativity. As general economic malaise is hampering spending habits, stores need to find new and unique ways to increase revenue. 7-Eleven, surely not immune to the ravages of the economy, is working on an interesting strategy to boost that revenue: Dabbling in the mobile video game space. Seriously. In a promotional announcement, 7-Eleven revealed that it is teaming with legendary video game franchise “Tetris” to release a special “cup” that’s really a handheld game console. According to the gaming news websit…