Sorry---I'm of no help on Friday flights. I'm heading up Thursday in order to attend my 20th Opening Day at Fenway Park on Friday.
However, I can tell you that the 3 post 3pm Thursday dca-ewr flights are quite full. The earlier one (1230, I think. Maybe 1:30?) still has room, but I'm not sure I can get out of the office THAT early.
And yes, I know about the train between DC-Boston. The last time I took it was I was in my first year of college, eons ago. It was spring break and I had to stand (or perch on arm rests) the entire ride from Boston to Philadelphia.
[This message has been edited by joanek (edited 04-03-2001).]