I see a lot of people, using dhcp for their lan, and don't understand the benefits.

I'm used to static IPs.
My example is: I have a /etc/host:
192.168.4.2 desktop
192.168.4.3 laptop

To make a filetransfer, I start
Code:
ftpd
on the desktop, and
Code:
ftp desktop
on the laptop.

When I use dhcp, will the laptop find the desktop too?
I need a hardware-router for this - or an additional service running permanently in the background, don't I?