Band-aid Advanced Healing Blister patches… see this link: http://www.bandaid.com/productList.do?typeId=4#anchor12 …. I sometimes put a strip of duct tape over these if I am running super long or going to get my feet wet or muddy
Bodyglide: rub on blistered area before putting socks on: http://www.bodyglide.com/ … works for chaffing anywhere
Make sure you are NOT wearing cotton socks… they don’t breath and therefore promote the formation of blisters due to when they get sweaty they stay sweaty and cause chaffing
When all else fails…. I know this does not sound great but in dire circumstances what really works during the run is putting some athletic tape on the blister and re-enforcing that with duct tape. Duct tape is awesome, does not move even when wet and causes no increasing of blister… had to do that during a trail marathon where we crossed 3 streams and feet were cold and soaking wet with over 13 miles to go… worked awesome.
Hope that helps. Happy miles.