Embedding a twitter timeline is a great way to communicate with people visiting your mobile site. Recently the twitter widget setup changed but all for the good.

As an example if you are a bar or restaurant you can tweet at anytime quickly and efficiently. Have a lunch special or happy hour? Tweet it out and it will instantly be available on your mobile site so people can see. If you do this on a regular basis, you will have people opening your mobile site all the time to see what you have going on. Always promote interaction with your guests and or customers and this is a great way to do just that. I use this a lot as a Recent News tab on the the mobile site for customers.