said by ymhee_bcex:
But I feel that you mean something else.
"Calling card" providers such as Localphone, Rebtel, Zenofon and Fonworld have a small block of numbers in each city where they provide access. You first enter your contacts' numbers on their Web site. and they display a (non dedicated) number for each contact. You must also register (and verify) your numbers on the site. Once set up, to make a call, you simply dial the access number corresponding to your contact, the system recognizes your caller ID and routes the call directly to your party, without your having to interact with an IVR. This is the mainstream usage of such services.
On Localphone, calls to iNum are free. You can set up your Latvian friend's number as if it were yours, and set up your (Localphone, VoxOx, etc.) iNum as a Contact. You set your Location to Latvia. When your friend dials the +371 6765 xxxx number shown for your contact, it will ring your iNum, without her having to enter any DTMF digits.
With Rebtel, it's a lot simpler, using their "collect calls" feature. You set up the iNum as your number and set up contacts in the normal way. You can expand the display for a contact and it will show a number for them to call you. As with Localphone, the call to iNum is free.