I have a friend coming to stay for a few days, will she be able to use AB with her own username on my pc, or will AB think i am using another name and zap me
Yes you can, my OH and I often forget and post something with each other's names because one of us forgot to log out and left AB open, and the other sneaked in. All you have to do is log out so the other ABer can log in!
You could always get her to use an internet browser that is different to what you normally use e.g. if you use Firefox let her use IE. That way the cookies are separate and you wouldn't need to keep logging in and out.
They may also be coming round with their own computer, in which case, yes, two computers can connect via a router to the same site at the same time and are totally independent.
thanks to you all, Chuck and ummmm, i have been around AB for a long time with other names of course, Chuck i can remember you starting on AB, ummmm, i remember you going to the other side for a long time, you are both top Abers.