How do you suggest to someone that they drop in on you? My dictionary suggests "fare una visita improvvisata", but I'm guessing this means to drop in unannounced. When I use the phrase "drop in" in english I'm not sure I actually mean that.

I am trying to suggest that someone drops in for a quick visit when they will be in the area or when it is convenient for them but I guess the "when it is convenient" part is implied by me in english. Maybe drop in doesn't actually mean what I think it does in english either.

I am forever finding out that I don't even use my own language efficiently so how can expect to speak another one?

If for example I lived in Rome, I would say "se capiti a Roma, vieni a trovarmi"

Are you sure you want to invite people to drop in? It does mean "arrive unannounced" in my book. It generally means that you will have visitors on your doorstep just when you are in your oldest clothes, the cat has been sick, you've run out of milk, you have a pile of laundry to do and you haven't dusted in ages because you have been so busy.

Vasco is correct. "vieni a trovarmi" means come find (visit) me, you could add "in qualsiasi moment"..anytime.

Art

"passa a trovarmi quando vuoi"