Should you stay friends with an ex?

Should you do it?
Well, up until recently I would have said, no way, just try and move on.
But now I'm not so sure.
When I first split up with my ex we said that we would stay friends, but that was mainly because we had tickets to Leeds festival and neither of us were willing to give those up.
But as soon as we had been there, I just found it too difficult to be his friend because I couldn't bear the thought of him with anyone else.
So we agreed to call it quits and not see each other anymore.
And my ex stuck to that for a couple of weeks but then he started getting in touch again and it was great and we chatted on the phone for hours as if nothing had changed.
But then I found out he was with someone and I cut him out of my life again, which I thought this time was for good.
But after all this bad weather we have been having, he called me up the other day because he had been stressing about me driving in the snow!
And he asked me if we could be friends.
Now, I haven't seen him since August - except for the odd few times when I have driven past him in my car so I am thinking it might be nice to have a good catch up.
But at the same time, I don't want to end up right back where I started.
So, in answer to the title of this post...I will let you know because I still don't have the answer!