Is it possible to echo what your mic records to the speakers?

I would take a look at Rogue Amobea's application LineIn. LineIn is a free app and can be found at http://www.rogueamoeba.com/freebies/.

From Rogue Amobea's site:

LineIn is a simple application for OS X to enable the soft playthru of audio from input devices. In simpler terms, you can use LineIn to play sound coming in through a microphone or any other device plugged in to your Sound In port, just as was once available with OS 9's "Play input through output device" option.

It can. If the program you are using allows it. But realistically go into the sound prefs and have it where the input is via a mic, and the output is via the headset. This should do what you need.