before JD shut down the first time, Doog did some stats on longest losing and winning streak at 49.5%.
I believe loses was as big as 32 in a row, and wins was 19 or 20.. i'm not 100% sure of the stats. its in the old JD thread somewhere.
Remember that this isnt simple 50/50. at 49.5/50.5, the max loss streaks will be longer than the max win streaks. (thus you can see the house edge in action, sortof)