A Church Lady's knitting bag shouldn't be without a few safety pins.
Here is what a safety pin can do for you:
-Prior to your cast-on (and I'm partial to the cable) wind up extra yarn for seaming and pin it in place. One less end to weave in!
-Find a safety pin the same length as your increase/decrease row interval. For easy knitting on the go, if you are increasing/decreasing every inch, attach a safety pin that length into the increase/decrease, and use it to measure your progress. When you get to the next interval, unhook and repeat.
-Much better than straight pins for anchoring seaming
-Use it to thread elastic
-Use as a stitch holder for patterned socks