"I" found an object left behind after a Jewish event in a public venue (let's say a hotel). "I" don't know who the owner is. The owner will likely come back to the venue to ask if the object was found.
"I" picked it up, so now "I" am responsible to return this object to the owner. Can "I" leave it at the front desk, or the equivalent thereof, for the person who lost it to find it there?
What if "I" can send out an email to a list of attendees telling them that whoever lost their item can get it at the front desk?