I do keep in touch with many of my ex's.
I am still very close to Ryan to the point that we talk weekly. (For those of you who don't know he broke up with me because he was diagnosed with HIV and didn't want to hurt me)
I actually work with one of my ex's, Joey, very closely on a community outreach program at the highschool ... it isn't too bad, we're both still very friendly and occasionally go to Starbucks.
I am best friends with my first ex, Meg. She and I dated for three years in High School and we are still very close. Without here I don't know where I would be today.
So, the answer is yep.