my husband and i started chatting and emailing each other wayback march 2005. when he filed the K1-129 application he included plentiful printouts of our email correspondences and everyday chatlogs. he even included couple of cd's of our chats (most of our chats lasted 12-14 hours almost everyday) so if he will print it out it will be 20-25 pages.
during my interview i brought along printed emails ( 2-3 emails/week), chatlogs ( 2-3/week), ecards, snail mails, postmarked cards, phone bills and phone cards (hundreds of them smart/globe/pldt budget cards). i brought everything that i can think of that will satsify the CO of how genuine our relationship was. so you can imagine how loaded i was during that time
but to my dismay, nothing were asked by the prescreener nor the consul. the prescreener just asked for my BC, my kid's BC, CENOMAR, affidavit of support, husband's 2006 W2 and tax returns. i even offered other documents that i have but he said that i had enough. so that's it! anyway, just bring all necessary documents that you have in case they will ask you for it. you will never know what they would want from you. it's better to be prepared! and of course, don't forget to PRAY!
GOOD LUCK and GOD BLESS!
ana