When someone says a club is "tipped" 1/2 inch...what does that mean? Thanks.

It's tipped to make the shaft a little stiffer.

Shafts can be butt-trimmed or tipped. Tipping is cutting from the tip end. Butt-trimming is from the grip end. All other things being equal, tipping a shaft will make it play more tip stiff and stiffer. You need to be careful on this....half an inch will make a huge difference in how the shaft plays.