Ncat is the updated version of Netcat that ships with Nmap. You can use it to connect over TCP ports and send/receive ASCII data. One fun thing to try is to test your knowledge of the HTTP RFC by browsing over a command line. How far can you GET, PUT, and POST your way thru a website? Bonus points for acting as a HTTP server.

Browse a website over HTTP:

C:\Program Files (x86)\Nmap>ncat www.jwgoerlich.us 80
GET / HTTP/1.1
Host:www.jwgoerlich.us

Browse a website over HTTPS:

C:\Program Files (x86)\Nmap>ncat www.jwgoerlich.us 443 --ssl
GET / HTTP/1.1
Host:www.jwgoerlich.us

Create a webserver:

C:\Program Files (x86)\Nmap>ncat -l 127.0.0.1 80

Traditional telnet can be used for browsing over HTTP, but telnet cannot to HTTPS or serve as a webserver.