No, not really - you would need to get an external program to really do that.
You can try arp -a which will show all the arp entries you computer knows about but that will only show things on the local subnet your computer is actually talking too.
You can also do a netstat -an which will show any established connections to your computer.
Lastly you can do a ping to the network broadcast address but that address depends on the size of the subnet on your network.
For example is your network is 192.168.100.0 with a netmask of 255.255.255.0 the broadcast address is 192.168.100.255.
if you ping that address then all hosts on that network will answer, if you're using Linux/UNIX you'll need to add a -b to the end of the command. Most routers won't allow this sort of ping to occur.
Your best bet is to use an IP scanner like this one:
http://www.angryziber.com/ipscan/