We throw a couple of blue or black ball point pens in our carryon for the immigration/customs paperwork. The flights never seem to have enough to go around.

Speaking of the paperwork, I print a copy of the form ahead of time and fill out the information that I don't have memorized (flight info, passport number, etc.). Then, when it's time to fill out the real form, I have the data in one place and I don't have to dig around for the answers in a cramped airline seat. Here's a link to the form.

http://www.jamaica-info.de/images/immigration.pdf