http://www.linux-sec.net/Audit/nmap.test.gwif.html

This site runs a basic nmap scan against your computer. Sure you could just run nmap locally against yourself, though you might want to walk around your workplace and check each workstation locally.

Sometimes you can't completely check the security of your remote computer because a firewall filters your intrusive scans. So get past the firewall via sitting down locally and running this link.