I just press login like at the same time, but cropping the browser to where login on both account are by each other and click login real fast
^^ hard to explain lol
Well, I have 2 computers, so it's fairly easy for me. But as other people are saying, just fill in the info on both FireFox tabs, both IE screens, or whatever, click "Log in" on one then click the other one and press Enter like it's your job. I haven't ever tried with SK / FF, but that might work also. Hope this helped!