I have never created an e-portfolio, but have wanted to for a year or two now. In fact, my principle would like all the teachers in our building to create an e-portfolio for this following school year and am THRILLED to have such a head start!
As for how my school currently uses e-portfolio...it doesn't. One of the main reasons my principle is starting this initiative this year is so that the follow year all of our middle school students will be able to start their own e-portfolio. Our district just approved having 1:1 netbooks for all of our 7th graders (piloting a new program) and creating an e-portfolio would just be the next step for us. Since the students will have access to a computer 24/7, keeping their course work/ refections/ projects in a portfolio would be so simple. :)
I also think that it would be great for teachers to share their portfolios with one another to share ideas and it would be an excellent way for different content areas to "see" what each other is teaching and how they are reaching their standards (what types of activities, technologies, experiences are the students getting).