You could have wiki, characters, items, maps as seperate tabs. Click on the tab and you get a list of all posts in the that section. Check the boxes of the ones you wish printed and then click print. This would allow GM's and players to print a bunch of notes quickly and easily. As currently set up, printing is a pain. I have to cut and paste to word then print. This is time consuming and a print function would go a long way towards making OP great. Another aspect of this would be to print all the items clicked in as little space as possible. perhaps creating a line break on the page after each clicked item. This would allow someone to print alot of wiki pages on a few peaces of paper. I realize that the formatting for this may be difficult but I do hope it is possible.
"Star Trek Late Night":http://www.obsidianportal.com/campaign/star-trek-late-night/wikis/main-page