The best way to contact me is via email. My personal email is j e f f r e y - at - g m a i l - dot - c o m. Please remove the spaces and the symbol instructions to get the full address.
You can also reach me on Google Hangouts via the same address. Likewise for FaceTime.
If you are one of my students, my email address at GaTech is j r a n d o w 3 - at - g a t e c h - dot - e d u (same rules apply)
In real life, I’m rather hard to contact because I tend to stay away from the limelight and hide in the face of attention. :)