Server load would be immense, as far as I'm aware, and I think this has come up before to no avail, so probably a 'no-no'. Wait for dRD or Ketola to reply, though.
This has been requested many, many times and we actually had this feature in place 3-4 years ago, but it killed the database. And as we've multiplied our traffic since then, I'd assume it would still kill the database, despite the fact that we've upgraded our servers two or three times since the last test. So, wont happen.
if you want to see if your buddy is on line or not just add them to your yahoo msg or any of the many buddy alert programs, how easy was that?