I use this activity with my Spanish 3 class. We work on reviewing eight tenses (present, preterite, imperfect, future, conditional, perfects, progressives, & commands) all at once to be sure they really have the conjugations.
For this activity, you need one set of regular dice with numbers 1-6 and one set of ten-sided dice with numbers 1-10. I bought my ten-sided dice here: http://biffleys.com/10sidedspanishwordnumbersdiceonetoten.aspx, which is cool because the numbers are written out in Spanish! Each student rolls both dice, and conjugates the verb for that numbered space (page two) according to the subject indicated by the number on the regular dice and the tense indicated on the ten-sided dice. The number 6 on the regular dice is used as a "wild" in our class, since we do not practice vosotros; however, you could easily have your students use 6 as vosotros, if you do practice it.
It is always great to see the students conjugating rapidly and correctly in eight different tenses! Enjoy!