You would need a separate journal to play with. Anne went through and made a bunch of journals for main characters, so if it's the actual *creating* part that you don't like, you could always use one of those.

If it's the switching of accounts, and you use firefox, there's this handy little plug-in: LJlogin. It makes going back and forth so much easier!

But I understand this sort of thing is not for everyone, so no hard feellings if you'd rather not ^_^