What about the crystal?
Good point! How about (T)ime, (D)ate, (C)rystal, (L)ogo and (R)otate? The C key is pretty self-evident in that it would simply toggle the entire crystal on and off. The T,D and L keys could perform a dual function. For instance, hit the T key and it turns on the clock and leaves it on the crystal all of the time. Hitting it multiple times would step through the clock styles so that you could select the particular clock style you wish to use. Similarly, the D key could do the same for the calendar and the L key for the logo(s). The R key could then be used to toggle on/off a "rotation" mode where the selected Time, Date and Logo are cycled through (ala v2.6).
A set up like that would let the user display just a clock or calendar or logo on the crystal or let them rotate through all three. It would also let them select the particular style of clock and calendar they wish to view as well as selecting the particular logo.
The only drawback I can see is if you wish to add in an option for displaying multiple logos.