Going on 2 week Italy (Rome, Florence & Venice) first of May. Would I be out of line if I posted a brief summary of the day's events? Would I make it a new post each day or just add to the first post?
I would describe your trip plan in the thread introduction, then add a post as you run across things that might interest other travelers to that area. I wouldn't suggest being locked into once-a-day. But once every 2-4 days as seems appropriate would be fine. What people look for most in trip reports are things like; "I didn't realize that...", "_____ was better than I expected", "_______wasn't really worth it", etc. Basically, people want to hear about things that would differ from or augment a guide book, and not simply replicate what could be found in a guide book.
I think you would need to make a new post in the same thread each day, or every few days. I actually like reading people's travel blogs noting what they did each day-if they are well written and entertaining. :) Go for it!