I'd like the posts I haven't read yet to show up as 'new' instead of the posts that have been made since last login. The 'last login' system is flawed because it assumes that you read everything of interest to you every time you log in. With the limited and interrupted time I have available combined with a relatively short timeout on inactivity, this is hardly ever the case for me.

There definitely has been a plugin available for some time for phpBB that does this, so I'd imagine there's one available for other major forum software also.