Another good tip is hotloading modules when you are in pvp. While you are warping in on a target you can click on your guns/web/scram whatever and click on an offgrid object in your overview. Doing so will cause those mods to flash as if on standby. WHen you land on grid and lock your target, the mods will activate and fun times are had. Its a lifesaver if you are the initial tackle (don't know how many times I had locked up a target only to have them warp off since I couldn't activate the scram/point on time).
Far as I'm aware, hot-loading don't work anymore. It simply says 'you can't target that' or something in that regard and then cancels the move. You used to be able to do this locking yourself as well, but nope, not anymore.
You're mixing two different things up. It used to be possible to "hotlock" to break gate invuln, ie, jump through a gate and F1+click target on the overview to decloak. They broke that a year or so before breaking the scanner, making scouting and tackling that much more annoying. You now have to double-click in space, wait 45 seconds for the server to recognize that you wanted to move, and THEN start locking to tackle. Which invariably leads to people in fat-ass ships warping off before interceptors can tackle them when they jump after them. No, I'm not bitter at all.
What Meli is talking about is activating modules before having anything locked while you're not cloaked. You can "hotlock" so long as you're not cloaked. The problem I run into is with hotlocking with a point activated seems to lose tackles sometimes--you'll lock, but your module won't activate right away and the target will get into warp. I prefer to lock the target, and mash F1 as soon as I see the lock complete.
Fun tip that I didn't know until a few days ago: when someone's jumping into you and you're waiting for them to decloak, have your cursor ready just below the last thing on your overview--the second they decloak, they'll appear there before the overview sorts them to their rightful placed based on your settings (distance, name, etc), allowing you to lock them before your client is even done processing the fact that they're there. Allows you to lock a good second faster, and quite handy for catching things that typically are hard to catch.