you can get them from digikey.com as well.....their shipping is $8 (at least it is to Canada from Minnesota).
It's worth it if you get a bunch, like 10. cuz the boxes are about a dollar, plus 8 shipping. $18 for 10 boxes is pretty good. You can get push switches from them too.
they have GAZILLIONS of items so it might be hard to nail down the parts you want, but they're there.