My squad, VF 15 Satan's Playmates, play Knights. So I play Knight when my squadmates are around. Often, they aren't. Then I'll either fly with some other Knight squad, or if some Killuminatis are on, I'll switch to Bish and fight with them. I'm a member of the Killuminatis in the Friday Squad Ops special events arena.
I used to hold this "I'm a knight" identity pretty seriously, and think badly of switching sides, but then I got involved in the FSO (friday squad ops) and scenarios, and started flying with a lot of different people, who play on different sides in the MAs. I would be flying with guys I knew as Bish or Rooks in the MAs, and killing guys who I knew as Knights in the MAs.
It made me realize that it doesn't really matter which side I'm on. The game is the same, only the names are changed. And once you get to know enough of the people from the "other side", it becomes fun to go over and fly with them sometimes too.
That being said, I don't take any information with me when I switch, such as the location of Knight or Bish CV groups, or planned missions or whatever. Doing that would be pretty lame.
ps: oh, and I don't go Rook. Yeck, that would be just awful...

pps: just kidding, though I seriously haven't found any good reasons to go rook for a very long time.
