How, it is still logging in as another user?
I think there is a fine line when it comes to "duplicate" suggestions. They may be essentially the same but the way they work/implemented and suggested by user-x will differ. I wouldn't want to keep logging in an out to go into another account (I can do this already) whilst a toggle between accounts would be a more appealing option (if i read slavik's suggestion correctly). Essential for test sites where we could switch between accounts since right now i have to either log out or load up another browser.
I think the suggestion warrants it's thread and see it has a sound enough suggestion with a difference. Infact, this suggestion comes with more info and more thought put into the initial post.
Exactly that Shelly says, the other suggestion would allow me to log into "Bob123" via the admin... I don't want nor need the ability to log into a users account unless they ask me to. Besides, going to the admin panel to switch into another account is even worse than logging out and logging back in.
This way, when logged in as "Slavik" I could then authenticate via my other username and password "News Account". Add a simple button into the UI somewhere, and in 1 click I can switch from Slavik to News Account and back.
Potentially even maybe something like the ACP, where clicking a tickbox or changing a radio option will give you an Ajax message that you've switched accounts, but without a page reload. The benefit of this is I could write up a post as Slavik, think oh crap, wrong account, and change to the News Account and post the news without having to copy the post, log out, log in, make the post, log out and log back. This way its quite simply, tick a box / radio button, make the post and change the tickbox/radio button back. Much easier, much cleaner and much more efficient at managing multiple "Site" accounts.
(For example, on P8nt I have my personal account, the admin account and a news account, so rather than having to go through logging in and out of each one 5 times a day, a simple switching mechanism will be much apreciated)
It could even be expanded to include sharing of accounts via this mechanism, Eg, I could set up all my mods aswell to be able to log into the news account and post things they find relevent, just by getting them to authenticate to the account.