In every town and some of the small vilages! Telephone
You can make international phonecalls in the phonebooths situated usually in the central area of the cities. There is a big board with the prices per minute (not everywhere). It's VOIP connection so not always best quallity but much more cheaper then calling from the post office.
In the post offices.
Internet cafe's you can find everywhere. It is cheap - prices vary from 1.50 lv to 0.70 lv per hour. There are also 'night-offers'- you stay for whole the night, for example from 00.00h untill 8.00h in the morning and you pay 3-4 lv. It's a good option if you're homeless in the big city;o)