If you are not familiar with twitter, it is a microblogging application. You can send short messages out and others can follow what you are saying. It is almost like a cross between instant messaging, blogging, and a message board. If you want to follow me, my ID on twitter is linniccox.
Skype is a free service that allows you to make phone calls to anywhere in the world on you computer. It also allows you to instant message and video conference. My skype ID is linniccox, join me there as well.