Add a checkbox to the login screen (like Wikipedia) that says 'Keep me logged in for  days'
Allow the number to be edited
I use IdeaJam most mornings, it's a pain to have to log in every time
I'd be 90% more likely to actually vote on an idea if the links from the IdeaJam Activity Summary actually logged me into the site. If I have to go and dig out my login details, most of the time I just don't bother.