ID Event Shortie gaiters are nice medium-duty gaiters by UL standards. 2.5 oz the pair for the current version.
They work with big boots, I use them off the trail to keep from having to stop and clean out my boots. Snow, dirt, rocks, sticks.
They are also nice for keeping the bottom of pants dry. If you are snowshoeing for instance, you can often wear plain nylon pants or even jeans with no prob.
No velcro or zipper, so you have to put them on ahead of time.
I am considering the non-ul OR Salamander gaiters for multi-day snow-rain hiking without snowshoes.
Edit: oh yeah, in the "you can live without them" vein, I have some great old nylon jogging pants where I have walked on the hem and the angle cinch elastic came out of the back half, so I just pull it down and around my heel. Voila-dee-dah, works well in all but snow. Someone must make a clip you can attach to pants hems.