We are all familiar with the current method of targeting players and monsters to cast your spells directly at them, or at least most of us are, anyway. Well...that method bloody sucks, if you ask me. Ever tried locking onto another player with 5 speed, while trying to avoid his attacks? It's damned near impossible, and very very dangerous if you miss. Although there are one or two ways to do it easily, they are still fairly risky and such.
My proposal is to make spell targeting a point,click,fire affair. So:
You point your mouse over a player, you click on the player, it targets the player (displaying the message "<accountname> targeted!") and you can then fire spells at your leasure. To un-target someone you can simply click on empty space, or on another target
This'd be so damned useful, i tell ya, it'd take some of the edge away from the fact that casting spells takes forever.