If you're taking vitamins or pills that are too large, the Apex Carex vitamin / pill splitter might give you a hand.
The clear plastic container has a razor built into it, and a sliding plastic shield that helps make sure your finger doesn't get nicked. The shield only slides away when the unit is closed and the pill or vitamin is being split.
There's a nice, wide base to squeeze down with, with a textured blue part to press down on. There is a small pocket to carry a few pills or vitamins with you, too.
Compared to other units that were hard to use, this one is nice and easy. Put the pill in place, press down on the large base. It splits right in half. I do have to warn that if you're splitting pills to make them easier to swallow, now the smooth, round edges of the pill turn into sharp pointy sliced edges :) So I highly recommend just getting pills in the proper size in the first place, if you at all can.
For calcium pills, which are a pet peeve for me, I get the chewy caramel squares that give you calcium without having to swallow a horse.
Lisa Shea's Library of Low Carb Books