'Is there a way to connect to a another mac without having a .mac account?' - yes.
Macs can be connected with a FireWire cable, an Ethernet cable (directly), Ethernet cables (via a switch or router), and wirelessly; even, via the internet.
I never tried connecting two Macs via a USB cable; although, it may be possible.
Other ways to transfer files: USB drive(s), CD / DVD disc(s), external FireWire and / or USB drive(s).