Easy to find your roots in Tinn and Gjerpen
On RootsWeb you can find large family trees with several thousands names from Tinn and from Gjerpen in Telemark. If you know the names of the people who emigrated from Tinn or Gjerpen in Telemark you can hardly miss finding many more members of their families on RootsWeb.(more).
On Sherri's Family History you find 32.833 names from Tinn, other places in Norway, and from America. Look up typical Tinn-names like Gjøystdal (Gjoystdal), Rollag, Mårheim (Marheim), Såheim (Saheim), etc. and you might be on the track.
Regarding Gjerpen you have names like Ballestad, Venstøp (Venstop), Hoppestad, Meen and Kise which are rather unique for the Gjerpen area. The Nelson - Seiberlich Family have 39.019 names, including a lot from Gjerpen in Telemark.
The RootsWeb pages also give you e-mail addresses to contact if you have questions.