Wouldn't it just be easier for the person who has the item to just right click?
Yes, but that'd be handing you results on a silver platter.
That's sort of what JAGeX is trying to do, make it easier for players, but I wouldn't like it too easy.
Or, you could just have an in-game timer. Like... a little box that says:
Abyssal Whip: Return to owner in 2 hours 15 minutes
Maybe I'll make a fake for it...
Alright, I made a terribly simple fake of a timer.
I suppose it could go somewhere on the screen, but it'd make the entire interface a clutter.
Maybe your right click suggestion is better, but it'd take a lot more memory for the servers and may increase lag.
Your fake would be good but where would it go? Maybe a little smaller in the top right hand corner or something, Anyways they should put SOMETHING in.