[quote=@The Fated Fallen]
<Snipped quote by Dragoknighte>

Easy way to play someone else's character; Make them drink loads, and then if they say you weren't playing the character right just say they were drunk!
[/quote]

That, or read their posts on a few key topics, mimic their speech and cadence to the post and give a pseduo-replica of that character. Of course it will be mildly different in style, but most characters are defined enough to recognize certain patterns of personality.

Or intoxicate them... that works too.