Pretty vague post you have here. What specifically are you looking to accomplish with your Twitter account. Simply setting up a Twitter account and blasting people with 'buy this' tweets will get you no where. However, developing a following and trickling in items you are selling can be hugely successful or more accurately great at driving traffic to sites.
I never said I was trying to do anything, nor do I have any use for twitter. This question is for everyone who will use it. Answer the question.... how will you take advantage of the new feature?
I'm surprised it took them this long to add photo and video. In the case of vids...most popular have always been funny videos...they're the most viral that I've ever seen. So, post some funny vids that are embedded on ur site inside a flash player, and throw some ads around em. That's just a quick thought.