What are the odds!

When you run into someone by chance people often say:

What are the odds!

or 

What a coincidence!

(walking down the street)

Hal: Is that you Jill?

Jill: What are the odds! I haven't seen you in years.

Hal: Yeah, I'm in town visiting my folks.

Jill: If you have time later, let's grab a drink and catch up.

Hal: That sounds nice, I'll give you a call. Is it still the same number?

Jill: Yeah, it is.

Hal: Cool, see you soon.
 
Meaning I am surprised to see you here, it is a nice surprise. Folks is a casual word meaning parents.

(in a supermarket)

Ben: Hey, Jerry! What a coincidence!

Jerry: Oh, hi Ben. How's it going?

Ben: Pretty good, and you?

Jerry: Not bad, I'm just grocery shopping with my wife.

You might also hear a bit of an older saying when you see someone somewhere you don't expect to see them. It sounds a bit more formal.

Fancy meeting you here!

(at a party)

Greg: Maria, fancy meeting you here! I didn't know you knew Dan.

Maria: Dan? Oh, I don't know him so well. I'm here with my friend Chris. He works with Dan I think.

Greg: Well, it's a nice coincidence running into you here. How have you been?

Maria: Not bad. These days I'm...  

I just thought of a 4th related expression: "What a nice surprise!" you can use all 4 of these interchangeably. They have pretty much the same meaning. Any questions?

Have a nice week,

Phil