Can you trade items with other players?
Solution 1:
I actually figured this out, you simply have to be in a multiplayer session, go into your item pouch (not the bin), and select an item.
There should be an option to 'Give', although I was unable to give certain items away (Godbugs, specifically). You seem to be able to give items to anyone on your current online session.
Solution 2:
The online manual says, that you can only give items from your item pouch:
During online multiplayer, you can select items (with some exceptions) from your item pouch to give to other players.