Accessign assets per page/part

[BigAlUK]

Not sure if this is an issue, more a feature request, or I may be missing something, but is there a way to reference assets on other pages or in certain parts of a page? For example...

At a page level:
<r:find url="/banners/">
<r:assets:each>

/r:assets:each
/r:find

Or at a part level:
<r:content part="gallery">
<r:assets:each>

/r:assets:each
/r:content