In the iPod Library Access Guide, at page 16 (where it explains about media query usage) there is a description like this, after describing the usage for MPMediaQuery:
You can construct your own collections as well. This can be useful, for example, for managing the selections a user has made with a media item picker. Note, however, that collections are not mutable.
Filtering and grouping a mediapicker selected item collection - is this really possible? I looked at the guide thoroughly but could not find a sample for this...
Any help is appreciated - thank you very much in advance!