I've posted this to the Feature Request section ( Feature Request ) but I wanted to suggest the idea here too.
It would be nice to have the option to have sub-summaries in Browse mode "stick" at the top of the records that it is the summary for. That is, as you scroll a list of records, and there is a leading sub-summary, perhaps with the contents of the sort field for example, that the sub-summary would not disappear but "stick" to the bottom of the header until a new sub-summary scrolls up and replaces it. This is seen in many iOS apps.
If you like the idea too, log a request?