The answer is that you can't, they're identical, especially if they tell you that they're Alex while you're playing Burnout 3 with them and then later they tell you that they were Jeff.

I just wrote a short review of Burnout 3 which I don't intend to duplicate here except to say "!*#$@)(!@*#!@)#(*!@@%#!ASLFAD@!@##ADAS@!!@ADFAS!". Whew. Earlier today I managed to stay connected long enough to play in the late afternoon with a crowd which consisted of a lot of little boys home from (or skipping) school and British men well on their way to intoxication (bless five hour time differences and accents over headsets). After listening to 15 year olds squeaking out the word "fgt" at one another, I had to ask myself why I am attracted to a sex that could have such an unbelievably awkward developmental stage. "Yes yes your brother touched his penis and now he's trying to touch you, that is HILarious".

Although earlier I was quite agitated about the state of the multiplayer, it has been at least twenty minutes since the last time I played, which means my anger has lessened enough that I can rationalize playing again.