WIDGET <ul> and <li> styling question

Hi there -

I am trying to put some spacing between list items in the side bar on this site

www.musiczeitgeist.com

for some reason I'm not able to find the right CSS selector to manipulate the list items, particularly in the Recent Posts widget. for some reason all the selectors i've tried using via firebug havent worked at all. I'm still learning CSS so any help with this would be greatly appreciated.

Thanks

BC