The nicest time picker I've seen is the one from Dojo (but you'll probably want to JSFize that - someone suggested jmaki is good for that).
I'm just going to do this in the simple way, which is setting components in the SFSB and then having the SFSB handle it when persist() or whatever is called. At some point when a time picker is packaged and ready to go I'll try it.
Good idea - someone should put a request in JIRA if there isn't already one.
Icefaces are adding in component that may suit based on the Tomahawk schedule component.
I have no idea when its slated for inclusion.
Better ask them.