I believe it was 2004 wsop Event #7 $1K rebuy, where Negreanu ended up taking 3rd for $100k (& pretty sure there was a last longer bet as well... idk for sure, have heard lots of diff. stories about this one)
negreanu was a strange case tho iirc - pretty sure he rebought as many times as possible on purpose so he could get a ton of chips in circulation on the table and win them back after rebuys had ended. wouldn't work for non-pros who get moved tables more often i imagine, and especially not online
yah.
I find in some online rebuys you're often on the same table for the entire rebuy period.. especially in smaller -field ones (not in the massive field ones).