In my game, you can lift up bushes and pots (like in zelda). When you lift them, it puts the item in your inventory, and takes it out when you put it down. Here's the code for that:

Bush
icon = 'mapobj.dmi'
icon_state = "bush"
name = "bush"
density = 1
verb
Lift()
set src in oview(1)
for(src in get_step(usr, usr.dir))
if(usr.holding == 0)
usr.icon_state = "bush"
src.getitem()
src.loc = usr
src.verbs+=/obj/Light/Bush/proc/Put_Down
usr.verbs-=/mob/verb/Attack
usr.holding = 1
else
usr << "You are already holding something!"
proc
Put_Down()
set src in usr
var/mob/player/P
usr.icon_state = null
src.loc = usr.loc
if(usr.dir == SOUTH)
step(src,SOUTH)
flick("bushbreak",src)
if(usr.dir == NORTH)
step(src,NORTH)
flick("bushbreak",src)
if(usr.dir == EAST)
step(src,EAST)
flick("bushbreak",src)
if(usr.dir == WEST)
step(src,WEST)
flick("bushbreak",src)
sleep(5)
src.verbs+=/obj/Light/Bush/verb/Lift
src.verbs-=/obj/Light/Bush/proc/Put_Down
usr.holding = 0
del(src)

That works fine, but because i'm using the character handling library, if you quit while you still have the bush lifted, it will stay in your inventory when you log back in. holding will still = 1 so you can't lift anything else, but the Put Down command won't show up so you can't put the bush down. I've tried during Login() and Logout() to write code to drop the item by checking if(holding == 1) but i can't get it to either add the Put Down command or just del the item, i just get compilation errors and runtime errors.