I guess it's not that easy, because of the city codes.
Example:
If somebody wants to call me from within Germany, she/he dials 06032-86370. From outside Germany it's 00-49-6032-86370 (provided that 00 is the access number to intl.
calls). I guess this rule is valid for most countries now.
Okay, I'm waiting for your calls, but dont forget: "0ld Europe" is 11 hours ahead of DB time. LOL