i think times have changed alot , and being friends with opposite sex is not a new concept any more ...

my very good frnd male is married to my best frnd , and we still are frnds and in contact till date.... and if i can see in past , I am 100 % sure there was nothing more than frndship from both sides ....

I guess it depends also upon your maturity level and your relationship status as well :-)

for me it do exist a good frndship between opposite gender ....