Looking for simple tools for scanning LAN devices on PC or Mac

So I have been using this nifty tool on my iPhone called Snap. Now I’m looking for similar tools for Mac and for PC. Do you know of any?

(I Googled but perhaps I didn’t use the right terms and nothing obvious jumped at me.)

Snap looks at your wireless network and lists all devices it finds. For example, it found seven devices when I ran it:
[ul]
[li]the main home router[/li][li]a secondary router that has a separate network[/li][li]my Mac[/li][li]our media center PC[/li][li]a NAS device[/li][li]a print server[/li][li]my work PC[/li][/ul]And if I tap on any one of them the tool lets me know IP, manufacturer, “pingable”, and MAC address. I can then scan for services.
For example on the NAS I see many: FTP, SMB, Telnet, NetBIOS, HTTP, Line-printer, and HTTPS.

Any nice clean tight apps for either Mac or PC that will do this with a minimal of fuss?
I’m not looking for Ethereal/Wireshark kinds of things, more of a simple tool to show exactly what my iPhone does.

Try nmap.