Flipgrid's GridPals is available to any teacher who has a Flipgrid account. Through Gridpals you can find other teachers around the world who are looking to connect their students with yours for video conversations. If you're not quite sure what Flipgrid is or how it works, take a look at this video tutorial that I made last year.
Every year Edublogs updates a list of public classroom blogs. You can use this list to find examples of how other teachers are using blogging in their classrooms. You can also use this list to find other teachers who are looking for classrooms to connect to their own for written dialogue.