Hey!
Lol, I was shocked what I found while using IG L2Walker 1.50 on C4 server and then I reconsidered it and it might be very useful at some conditions, like in mass pvps or when you want to find dropped items, or prolly when someone hides somewhere 'cos they're scared of you. ANYWAY: By pressing 1 button (when using IG walker) all the items/mons/npcs/players will be significated with red transparent barrel. To do this, just press END button, while in game.
(In case it was already posted, cos I used search function and didn't find anything, I'll close this and let it to junk)
Screen: