This is another one that's been in the queue to update on here for a while. Screaming NetTools!
If you've ever been at a site and needed to scan an IP for vulnerabilities, establish a telnet/netcat session, run a whois, ping, dig, or nslookup, then this tool is for you!
Screaming NetTools is (admittedly) a niche tool, but for those of us who need it know exactly how helpful having the capability to do this sort of thing "on the road"!
Features: