jwoodget - For seeing whom is on your network check out NMapFE
. It does way more then you want, but for finding out everyone who is on the network (even if they have a firewall or are in stealth mode) simply tell NMapFE to do the following:
For scan type choose Stealth FIN.
For host just enter 192.168.1.* (or if your router uses the 192.168.0.x scheme enter 192.168.0.*)
Then press scan. It will then tell you what computers are connected to your network, and will also bring back a list of ports open.
If you want to you can also identify the OS each node is operating by selecting OS detection, however it takes longer for the process to occur.
Lastly you can ignore any occurances at x.x.x.255 and x.x.x.0 as they are addresses that are not used except for broadcasts.