There are printers with WiFi and/or Bluetooth, but to be honest I wouldn't pay the extra for that. My little portable one has InfraRed, as does the laptop, and that's nifty on a hotel room coffee table. I carry a USB cable anyway, just to be sure.
My router has a USB printer port, but it's not bidirectional so the computer doesn't see the messages from the printer about "need ink" or "need paper" or "wrong paper size, twit!". Both printers are connected to the desktop PC and networked from there - so anything on the network can use them and gets full bidirectional info.