You can find many public telephone booths in Aalborg, so you need not worry to make calls to your home, but it is costly. You can get international calling cards in some of the departmental stores; you can use those cards to make international calls.

For those of you who need to stay in close contact with others in Denmark, you can always get a cellular phone. Here it is GSM connection, so bringing a cell phone to Denmark will be useful. If you buy and keep a post paid card for 6 months with some advance (depends on the mobile phone), then that mobile phone will be yours :)

If you are allowed to use internet then use JustVoip kind of online VOIP to make calls that would be the cheapest.