Linuxluver:

 

If you're planning on talking for hours, then just use Skype or something similar. 

 

I have had excellent success with Skype to mobile to family in the US, very cheap too, dont really see a need to keep numbers.  I find it amusing that people think they have a "good" number and dont want to lose it, but the fact is, other than your own number people do not any longer memorise phone numbers.  I am sure there are more legitimate reasons to keep it running, but otherwise seems crazy with the alternatives.