I'd just like to add that another good use of this functionality is to set up multiple destinations for multiple environments. Then, using a String Table variable, you can specify who should receive this task. "Who" being whomever falls under the Destination.

For example, you can set up three destinations. One for Development (send me the tasks). One for Test (send QA the tasks). And one for Production (send actual users the tasks).

Use the following Destination Rules:

Development:
[{K2.StringTable("Environment")}] = "Development"

Test:
[{K2.StringTable("Environment")}] = "Test"

Production:
[{K2.StringTable("Environment")}] = "Production"

Finally, instead of selecting All True, select First True (well, All True should give you the same result, so ignore that if you want )

- Schap!

P.S. Thanks to Cherish for that tip!