You can buy foam tubing type insulation for pipes at the box stores. Insulate all the pipes you want to.

Heat in the basement also heats your first floor (boards).

Thanks, baymee
By the way, is it really OK to insulate ALL the pipes? There is no heat source in the basement...

You're going to have to decide how many pipes are necessary to leave uninsulated to prevent freezing on the coldest day of the year, a daunting task.

The main reason for insulating my pipes was because my boiler is 50 from my closest radiator and I didn't want to loose excess heat in the travel through my 65 degree basement. Otherwise, I'd leave the pipes uninsulated because the heat is all part of the greater effort in heating my house.

I never heated my basement and it never came close to freezing here in PA.

FWIW, the folks over at heatinghelp.com (almost all pros) told me the main line should be insulated as the heat lost warming the basement causes the boiler to operate longer to keep the water hot enough for the radiators (more $$ + less efficient). However, my mother's boiler company in the Buffalo (NY) area states the main pipe should be kept uninsulated for the same reason stated by baymee. All the pipes in the basement were insulated when we moved into the house but 7 kids "fixed" that. I'm not qualified to say who is right but the website moderator has written a couple of books on steam & hot water heat that are easily understood by the layperson.

Two years ago I looked at pipe insulation and found large pipe sleeves (fiberglass surrounded by a white fiber cloth) only at a plumbing & heating store. The sleeves were very expensive. You might be able to use the foil wrap insulation, used on ductwork, for a more cost effective insulation method.

BTW, it's going to take a lot of cold to get a basement down to ~30 degrees, when you would worry about pipes freezing.

One approach would be to insulate what you feel comfortable with this winter, and then put a thermometer down there that has min/max on it (buy one at radioshack). See what it gets down to on the coldest nights. Then insulate more next year.

Insulate the pipes running from the boiler to the radiator and leave those running from the radiator back to the boiler uninsulated

Don

Yes you get more bang for the buck insulating the hotter pipes going to the radiators.
Also, freezing temperatures in a basement is unheard of unless you are in Alaska.
So, any insulation you provede in the basement would be for energy savings only. Your worry about losing heat to the basement at the expense of the upper rooms is doubtful.

Thanks everyone for the advice!
I decided to insulate the pipe this year and adjust later if necessary.

By the way, I went to Home Depot and found this pipe insulation sleeve. Not gray foam ones, but black ones, called Armaflex. Is this good enough? Or foil wrap is better? Or anything else? something I can find at Home Depot or Lowes?

Any kind of foam insulation used for hot water pipes is OK. No need for foil.