Let me kick this off with easyplayer - a very nice file-based music player that I have installed recently.
"Preferences" here is a window, not a dialog (should be a dialog to fit with the rest of Maemo?)
"Use big buttons" does nothing or at least nothing obvious - maybe change the text to better describe what it does
The buttons are thumb sized - i know of other preferences dialogs that have finger-sized buttons; ideally, to create a "balanced look", preferences dialog should have the same button sizes (exceptions should be justified)
The "Stop playing after:" and "Display remaining time until timeout" belong together somehow - they should be grouped visually (e.g. a header "Timeout" for both buttons and remove the "until timeout" from the "Display remaining time" button)
Is it really necessary to have a text input field for the "Stop playing after" selector? There are 6 elements in this list (5 min, 10 min, 20 min, 30 min, 60 min and never) and the list displays 4 elements at the moment, without the entry field 5 elements are visible
Often there are choices where the user can select some interval or "never" - should this "never be placed at the beginning or the end of the list? Here, "never" is the last element, other apps place "never" where 0 would be placed (I personally prefer to have "never" sit where 0 would be placed. i.e. *before* all other items)