I know that many Americans are looking for relatives living in Norway today. Very often it is difficult to trace these relatives.
The reason for this is that most sources needed to trace family-relations in the 20th and 21st century are protected by law. They are not released until at least 60-80 years after the last entry was made. For the same reason it is very difficult for me to put you in contact with relatives living today. In some cases there may not be any relatives in this area at all. If you are looking for relatives living today let me know, but I do not promise any positive outcome of such an inquiry. However in some rare cases I may know them, or know someone who knows... .
In case I cannot help you to get in touch with your relatives, the best way to try to establish contact is probably to put an advertisment in the local newspaper. This paper's name is GD, and their website can be found on this address: www.gd.no . Whether they will publish an advertisment or not, I do not know.
To have a reasonable chance of getting any answers after such an advertisment, however, you need to supply as accurate and recent information as possible. Many people in Norway (as in the US?) do not know the names of their great grandparents, unless they are interested in genealogy. Another thing has to do with names. Many Norwegians changed, or at least "americanized", their name when they came to America. In many cases the Norwegian relatives do not know the American name, only their original Norwegian name, so you should put some efforts into finding the person's Norwegian name unless you allready know it.
Many of the Norwegians emigrated as early as in the middle of the 19th century. Any "relatives" living in Norway today would be your 3rd, 4th and maybe 5th cousins. Most Norwegians do not consider this relatives and many people may not be very enthusiastic about meeting with that distant "relatives". This not said to discourage you, but you should take it into consideration when looking for relatives in Norway.