http://www.yougetsignal.com/tools/open-ports/
This is a very nice and handy website based set of tools:
- Port Forwarding Tester
- Network Location Tool
- Visual Trace Route Tool
- Phone Number Geolocator
- Reverse IP Domain Check
- WHOIS Lookup Tool
- iGoogle Network Information Gadget
- Windows Network Gadget (Vista/7)
