How does a plugin make use of Assets? Within my plugin, I have a need to open an Assets sheet and pick a file that has been uploaded and make use of it in my plugin. How is this possible? I am looking for something similar to the EE version of Assets that will allow me to programmatically use Assets with JS.
Something like this should get you going in the right direction:

Craft.createElementSelectorModal('Asset', {
    multiSelect: true,
    criteria: { locale: this.elementLocale, kind: 'image' }
});


See Brandon's answer here for more information and documentation:
Is it possible to use the ElementType Modal UI for a custom Field Type Plugin?