You just need to put the block on your screen, send a list of items (from an aggregate for example) and then you get the ID of the selected item from the radiobuttonlist, or a list of the selected items from the checkboxlist. 

You can configure an item "Other..." that shows/hides accordingly.

It allows yet optional parameters to be used in complex forms that navigate back and forward. 

For straightforward forms you just need the mandatory parameters.

Check the DEMO!