Is there any way of telling if someone is online?

You can get some idea if a user is on line by clicking onto the your fans. There's a section that says "last signed in." So, if there's 10 users signed in after you I suppose there's a good chance they ARE on line with you.
If you're really desperate, you can always stalk the homepage and see what users are submitting stuff at the moment,lol.

There isnt an "online now" button or anything- usually you can tell by peoples activity section if they are online or not.
i think having one has been discussed and got mixed reactions..its up to the f4 really.id be okay with it as long as there was an option to "show as offline" when i dont want to be contacted. but i dont really see the point as there isnt a one on one chat for users anyway. whats the point of knowing if someone is online then?

my closest fanpop buddies (yes, you know who you are :P) are on msn anyway.

you can tell by looking for a star at the bottom of the page.