Sometimes good things work under the bonnet and you just don't even know about it. The problem is that when good things have been implemented and you don't know about it you can really miss out on all the goodness!
For example avahi - this provides service discovery on your local network. With avahi one can add your computer into a local network and instantly be able to find other machines on the local network without the pain of configuring a server to run services such as DNS. For zero effort you get a top level domain (TLD) of .local - so if your hostname is called mypc, it's resolvable as mypc.local
Some of the details to how this was implemented in Ubuntu is detailed in the ZeroConfigNetworking wiki page if you want to see some of the nuts and bolts behind this.
If you want to discover the machines on your network, use:
avahi-browse -a -t
and you get output something like the following:
+ wlan0 IPv4 mynetbook [00:24:1b:7a:22:c2] Workstation local
+ wlan0 IPv4 delllaptop [00:1f:1c:cd:82:41] Workstation local
Use can use avahi-resolve-host-name to get the IP address of a machine on the .local TLD using:
avahi-resolve-host-name -n hostname