Via Simply Jews:
The rest of that psalm (the exact fate of the right hand) is disputed in its various English translations, but a recent case of forgetting Jerusalem should put an end to doubts:
Above the picture:
December 3, 2012: “Russian Foreign Ministry condemns the Israeli plan of building in Jerusalem.”
December 4, 2012: “The head of Russian Foreign Ministry, Sergey Lavrov, broke his hand in Istanbul.”
“If If I forget you, O Jerusalem, may my right hand dry off.”
Israeli Ministry of Health warns: fighting Jews may be hazardous for your health!