Kalimpong is about two-three hours by shared jeep from Darjeeling. Worth a trip (even if only for the views on route).
If you go to KP's Motor Stand & in Himalaya Travels ask for Gobinda Dradhan, he will take you on a (set fare) tour of the local sights - magnificent viewpoints and Dr Graham's home.
Best of all, Gobinda takes his time, does not hussle you into visiting shops and is very knowledgeable about the area.
Send your feedback or queries to firstname.lastname@example.org