Stacking 2960 with either 3560 or 3750?

Solution 1:

Answer: No

Source: http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps6406/white_paper_c11-578928.html

The important part: FlexStack is the name of the stacking technology used by the Cisco Catalyst 2960-S series of fixed Ethernet switches. FlexStack is specific to Cisco Catalyst 2960-S switches, and only Cisco Catalyst 2960-S Series Switches use FlexStack.

Longer Answer: No, because they use different stacking protocols and different physical cabling to do so.