please check this sentence

[venkat.daggumati]

it's been a long time talking to you.

[svartnik]

You are on your way home when a friend gives you a ring. You talk for a relatively long period of time. When you have arrived at your place you hang up and log in the MSN Messenger. The first sentence you type in and send the person with whom you previously had a telephone conversation is:

It has been a long time talking to you. My telephone bill will be huge.

IMO, it is fine.

[Raymott]

it's been a long time talking to you.

Your sentence is not exactly right; besides it's ambiguous.
You possibly mean:
It's a long time since I talked to you.
It's been a long time since I talked to you.
This means you haven't spoken to the person for while.

If your meaning is the one svartnik has inferred, then:
I've been talking to you for a long time.
I've been talking to you a lot lately.