Basically I'm working up a site that builds in a posting form on a page. (Yes, I've tried TDO mini forms and I really need some more flexibility before and after the form than it offers). If you need a visual, think of the Prologue theme posting box with more info added.
While I can get the rest of the form working, I'm totally getting lost in the php to get the categories working. It should function like it does on the backend with checkboxes. Populating and creating the checkbox list isn't the problem, it's looping through, converting to the id's, and figuring out how to format that into an array to send to wp_insert_post is where I'm getting caught up.
I've got everything else working... titles, tags, custom fields, etc... just can't get the cats right for some reason. I think I've hit the braindead stage and need to get some outside input.