Expensive overseas calls

My uncle keeps complaining to my aunt that it costs him a lot of money to call her from his mobile phone each day. He just got posted overseas and misses her a lot. Keeping in touch is burning a large hole in his pockets. My aunt was hospitalised some time back and he's concerned over her health. Too bad he cant be by her side all the time as he only gets to fly back for a short visit once every two months or so. And that's if his boss approves his leave. But he did say that his boss may be installing this Call Center VoIP Phone Systems that will help bring down the high cost of overseas calls. Hope his boss installs the system soon. With VoIP, my uncle can call back and check on my aunt whenever he likes.