My friend logged in on my computer today and afterwards logged out. I have their email and was wondering if there is any way I can login into their account somehow.
If you haven't closed the browser down that they were using for their myspace session, you can backpage and it will let you see all the pages they accessed during their myspace session. You cannot access further than just what they saw (basically you cant click on links, you can only view what pages they viewed). This is something I noticed last year about myspace. Even after you logout, you can backpage and see what pages you viewed on myspace. It can be very handy at public libraries

If your friend wasn't using firefox for myspace today, then you are not gonna be able to use the firefox store password feature for another browser. I think that firefox lets you import stuff from other browsers during installation but atm I can't recall all the specifics. But if they were in Internet explorer and chose "remember me" as you said, then you can probably login that way, I assume.