If you go to the person's profile and look at the "Last Update" it gives you an idea as to the last time any activity took place, but that may not tell you when he or she was last online. Someone might remain logged on without posting anything or without navigating, so the last update might not be an accurate gauge. I believe that's as close as it can be narrowed down. ~
You can't. Doing what Randy said will let you know when they were last active on the site, but people may remain logged on whether they are here or not.
I stay logged in, too. I do that with all my sites, so when my phone puked recently I had to figure out all my passwords and which email I used for different things...what a mess!
I try and write all my passwords down, but sometimes I forget where I put them LOL So if I get logged out, I have to figure where my passwords are to log back in, and yes it is a mess.
I do, too. I just have them written down here, there and everywhere. I have the same problems with my contacts. I had them both written down and on my phone...then burned both in a fire, so then I stored them online in my SH account and they booted us, then I backed them up in the cloud...so I restored them after I got this new phone, and the next day, they disappeared from both the phone and the cloud! Arrrgh!
Benedict Arnold 