The origins of Halloween are from very early times. It began approximately two thousand with the Celts in Ancient Britain and France and it commemorates a pagan rite where they would burn people alive in order to appease their god of the dead. After the Roman conquest Halloween "changed hands" and became a Roman festival day that combined the concepts of commemorating the dead and the harvest of fruits (which was symbolzed by the apple). As the Christian empire started to exert its influence on Britain (approximately 800 CE) Halloween went through another "facelift" and it became a day for commemorating the saints. That is when the name Halloween was given to the day.
While it is true that that modern day Halloween bears no resemblance to the original and today it is mostly a commercial affair, because of its pagan/Christian origins I would not recommend Jews celebrate it.
